ccanlint complained about it; it's trivial but fixing it adds one point to 
our score.

ccanlint did this automatically.

Also, add Author and License lines to _info (ccanlint complained).
Now ccanlint can build it as a module.

This makes it closer to compiling under ccanlint.

This means we can pass various compulation tests, but deduct points if
they get warnings.

We want to distinguish between warnings and errors: the first step is to
return the output even if the command doesn't fail.

Test for inserting idempotent header was wrong way around, and we check
all headers at once, rather than finishing after one.

Also, turn - into _ rather than removing.

This means we can see messages even if we don't fail; ie. for compiler warnings
once they are no longer fatal.

This means that various tests have to be more careful in not setting
score->error.

We only grabbed one character at a time from stdin, so "y<return>" answered
the next question as well.

Michael Ellerman noted that ccan/opt has no symlink, so add ccanlint test.

I am told that CentOS 5.3 doesn't like isblank (it's ISO C).

Delio Brignoli points out that check_type fails when HAVE_TYPEOF is 0,
so turn that off here and see what else breaks...

"C has fairly weak typing:" from check_type/_info is not a new section heading!
Enforce that each word in multi-word sections must be caps.

We used to prefer to build up examples using previous ones, but this broke
for tests which were to be executed.  But list.h relied on the buildup
behavior, so return to that unless we see "// Given" comments indicating
an execution test.

gcc with optimization complained (correctly) about this.

(nfs gives warnings on build, make ccanlint unhappy).

The long names were unwieldy in practice; at risk of clashing, replace
with shorter versions.

ccanlint won't run rpcgen, so we need the C source in the repo anyway.

rename libnfs.h to nfs.h (CCAN expects "main" header to match module name).
tools move into tools/, .x file move into rpc/
Don't sed the rpcgen files, generate headers in rpc/
Make tools use <ccan/nfs/nfs.h> as per normal ccan usage.

Another Ronnie module!

Previously each check returned a void *, but in fact most of them fell into
similar patterns.  So define 'struct score' and a helper to add files to it,
and use that.

Under these rules, you get 0/1 if you skip a test because a dependency failed
which in theory means your score (as a percentage) could drop if you fix
a test.

Make test directory correctly, and #include <ccan/...> not #include "".

I'm not a fan of the SHOUTING, but it's upstream.

With the extra bits, long runs don't hurt our cache very much on search,
so we can pack quite a few in.  Here are the runs at maximal density before
and after:

Before:
$ ./speed 3145000
Initial insert:  248 ns
Details: hash size 4194304, mask bits 9, perfect 63%
Initial lookup (match):  122 ns
Initial lookup (miss):  142 ns
Initial lookup (random):  170 ns
Initial delete all:  134 ns
Details: rehashes 3145000
Initial re-inserting:  149 ns
Deleting first half:  73 ns
Details: rehashes 1572500, delete markers 1572500
Adding (a different) half:  128 ns
Details: delete markers 0, perfect 62%
Lookup after half-change (match):  129 ns
Lookup after half-change (miss):  145 ns
Details: initial churn
Churning second time:  703 ns
Churning third time:  725 ns
Churning fourth time:  717 ns
Churning fifth time:  710 ns
Details: reinserting with spread
Details: delete markers 149261, perfect 57%
Details: worst run 254 (2 deleted)
Lookup after churn & spread (match):  132 ns
Lookup after churn & spread (miss):  159 ns
Lookup after churn & spread (random):  184 ns
Deleting half after churn & spread:  71 ns
Adding (a different) half after churn & spread:  129 ns
Details: delete markers 0, perfect 62%

After:
$ ./speed 3145727
Initial insert:  232 ns
Details: hash size 4194304, mask bits 9, perfect 63%
Initial lookup (match):  122 ns
Initial lookup (miss):  141 ns
Initial lookup (random):  234 ns
Initial delete all:  129 ns
Details: rehashes 3145727
Initial re-inserting:  153 ns
Deleting first half:  80 ns
Details: rehashes 1572864, delete markers 1572864
Adding (a different) half:  137 ns
Details: delete markers 0, perfect 62%
Lookup after half-change (match):  125 ns
Lookup after half-change (miss):  145 ns
Details: initial churn
Churning second time:  702 ns
Churning third time:  719 ns
Churning fourth time:  712 ns
Churning fifth time:  709 ns
Details: reinserting with spread
Details: delete markers 169474, perfect 56%
Details: worst run 248 (12 deleted)
Lookup after churn & spread (match):  129 ns
Lookup after churn & spread (miss):  159 ns
Lookup after churn & spread (random):  242 ns
Deleting half after churn & spread:  70 ns
Adding (a different) half after churn & spread:  133 ns
Details: delete markers 0, perfect 62%