also remove unused TestCase0

- core module gets a completely new interface, incompatible with gevent-0.13
- SystemExit, KeyboardInterrupt and SystemExit are now re-raised in the main greenlet
- Python's signal module works

__init__.py:
  - add get_hub to __all__
  - remove shutdown()

get_hub() now accepts arguments to pass the loop (e.g. get_hub('select'))

Hub class:

  - new methods: handle_error, wait, cancel_wait, join
  - removed method: shutdown (replaced by join())

Timeout class:

  - allow passing string as exception

coros, event, greenlet:

  - use hub's handle_error to report_error rather than traceback module
  - save hub as an attribute rather than calling get_hub() all the time

--HG--
rename : gevent/core.pyx => gevent/core_.pyx

replace get_hub().switch() with self.parent.switch - should be faster as it avoids accessing threadlocal

--HG--
extra : transplant_source : %1A%E6q%AD%D1mm%DE%D8%8E%A8i-%E2%5EB%BAsG%FB

--HG--
extra : transplant_source : %15%CD%D6%04%138.%C8%C2%1A%9Ag%B0%2C%3B%C6%C4%E4%A3%E3

--HG--
extra : transplant_source : %BF%DD%DB%95%12a%BE%8B%F0%FB/%60%8E%84%FC%05%C7a%95%19

--HG--
extra : transplant_source : 6%8F%8D%87%BD%7BXLzl%3Al%85%1C%7C%F8%F7%DA%09%07

--HG--
extra : transplant_source : %DA%21%A7%AD%5B%09%B2%A2%AAIT%D0f%7E%80J%C2%DD%86%0C

--HG--
extra : transplant_source : %EA%99%1F%0F%C0Gq%98b%A7%0D%95%ABo%14%CF%18k%20f

--HG--
extra : transplant_source : %1BC%DB%8C%C3K%94%B3%B6%AC6%8A%1A%25oKX%D3%97B

--HG--
extra : transplant_source : %11%87%A0t%3B%F8O%2C7%FFl%8C%10%9EB7%83%11%C5%95

--HG--
extra : transplant_source : D%06%07u%F3aE3%13%EF%85%A6%20%27b%3E%3Bg%E7%3D

--HG--
extra : transplant_source : %8B%03%9E_%09%15%DD%0C%EEv%01a%F5%A6%A8%D0%B9%C9%84%1A

--HG--
extra : transplant_source : %F7I%C0%01SF%98%8A%83%7F%B7U%BEW%A5%5DY%AF%DE%D2

testrunner.py: convert path to testresults.sqlite3 to work with tests that chdir (test__doctests.py)

--HG--
extra : transplant_source : l%21g%5B%B8B%B6%BA%DElz%9F%A6%5E%23%C9%B9%8E%20%18

--HG--
extra : transplant_source : %A5%5B%ED%F9%7C.%CA%84%18%A6%AD%93%2A%03%90%C6%B9%E0%D8%1F

--HG--
extra : transplant_source : p%03%AA%98Y%87%06%F1%F2O%7B%B3qnL%066%1F%A9%21

--HG--
extra : transplant_source : iM%EB%AA%A7%25hy%5Cn%81%3F%DDp%25%EE%D2%E1%A8g

--HG--
extra : transplant_source : %8D%01%FEP%F6%14d%15%C5%26V%FA%7B%CBx7GC%967

gevent.monkey: add patch_httplib() function and 'httplib' argument to patch_all() (disabled by default)