Move std C time APIs to libc.time; Move posix.sys_time to simply posix.time for system-level things like timer_* clock_*.

--HG--
extra : transplant_source : %1D%F7%80%B8jC%D1%83%0DH%FD%E1%81%26cqv%B7%1F%CE

--HG--
extra : transplant_source : %279%83%AB%FF%04%F0%F6%12%BB%D1P%19%A9%B9%F2%C6%C23%B6

--HG--
extra : transplant_source : %DA%97_%C9%8A%9E%ED%3F7%FC4m%1E%E6%0E%D3%89l%DF%D4

--HG--
extra : transplant_source : %D31l%C2%F1BM%00%92l1%99%C0l%E8e%FC%9C%0C%AA

--HG--
extra : transplant_source : %B2a%A7%A9%A6%2A%2C%21%11%A1%D3%A0%F4%0D%D1%C7K%97%60_

--HG--
extra : transplant_source : %A4%C2%DA%5EV%1C%17%07%E3%E9%9E%C7%AB%1EF%2C%C8%A7%1C%5D

--HG--
extra : transplant_source : 7P%DF%9E%F8%A3%2B%98%17V%CB%9E%EC%A3m%28G%1Bv%A1

--HG--
extra : transplant_source : %10%00%9D%98%A4O%02%1A%ACs%3F%92gB%E2%21%7B%1Eo%C8

--HG--
extra : transplant_source : s%10%909%A0X%06O%D6A%C6%DEEUM%80%15%3D%C7%83

--HG--
extra : transplant_source : %7B%A1n%8F%25%8E%DE%EE%CCQu%8B1%9Ea%B7%3B%19MF

--HG--
extra : transplant_source : %E4%89i%BE%1F%A4%29M%B5%3A2vK%8C%3E%93%EF1%A8%83

--HG--
extra : transplant_source : %3B%E2%B8%E5%8D%CC%B7p%CA%24%14%C3%D8%B87%A6%0Ej%A8%E8

--HG--
extra : transplant_source : %C1IR%7B%29%27%07E%19%1F%82G%CDLi%E1N%23V%9E

--HG--
extra : transplant_source : %1F%BE%A2%C2X%2C%AA%3F%AD%7D%07%A7q6%180%A38%CB%5D

--HG--
extra : transplant_source : r5f%D6%7E%D3%9C%0A%A0%1C%9FX%E0%F6ji%13T%00%A4

--HG--
extra : transplant_source : %CC%5B%1C%85Jy%96%C2%29%CDt%26%E0W%EB%0C8%DF%0Fb

--HG--
extra : transplant_source : V%1D%AF%BB%C2%E7l4%28%AE%8C%A9-%B0%B4%11%91%1B%FB%2C

--HG--
extra : transplant_source : %CA%C1%8A%A1%D8g%1C%B1%00R%CA%C2%09%11%08%CE%60IG%1A

--HG--
extra : transplant_source : 8wv%A8%80%0B%7D%CA7%C8%10%B7%E4-I%F4%D0%29%D7%CC

--HG--
extra : transplant_source : %C6f%B9L%06%0A%97m%15K%F7%CCN%90%B0%A5%90%04%96%A9

--HG--
extra : transplant_source : %FF%0B%A3%9D%21%85%A9%1A%8B%D1V%AD%CF%DD%3Em%92%DE_%8F

--HG--
extra : transplant_source : %5ET%93%08%03d%EFC%C5X%D7%03%28%C4%EF%1DO%CC%1A%7C

--HG--
extra : transplant_source : u%8C%DA%B6W%85%BC%FDA%A0%9C8%B6%16%86B%12%B6%1C/

Ignore any unused entry that starts with '_'.

In addition to '_', also ignore any unused variables whose name start
with 'unused', as recommended by http://google-styleguide.googlecode.com/svn/trunk/pyguide.html?showone=Lint#Lint