Epoll wrapper + selectors module.
Epoll now works.
Normalize whitespace in osproc.nim.
Introduce poEvalCommand, poUsePath, fix remaining quoting issues.

- poUsePath is now an alias for poUseShell.
- poEvalCommand should be used when shell evaluation is really needed.
It passes `command` directly to shell/winapi. Requires `args` parameter
to be empty.
Merge branch 'osproc' into devel

Conflicts:
	lib/posix/posix.nim
	lib/pure/osproc.nim
Adds AllChars constant to strutils.
Adds note about manual memory handling to GC doc.
Merge branch 'devel' of https://github.com/Araq/Nimrod into devel

Conflicts:
	lib/pure/osproc.nim
Fixes #848.
Finished logging module.
Punctation -> punctuation.
Punctation -> Punctuation; fix remaining typos.
Merge pull request #851 from EXetoC/highlite-typo

Punctation -> punctuation.
Avoids raising exceptions in tryInsertID.
added Cartesian product
forgot to export product
product more robust against empty input
sets equivalence
bugfix: object constructor doesn't allow 'distinct' types
documented new symbol binding rules for templates