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
Avoids raising exceptions in tryInsertID.
product more robust against empty input
sets equivalence
bugfix: object constructor doesn't allow 'distinct' types
documented new symbol binding rules for templates
Fixes wrong slurp path in tester.
corrected docs and tests
case consistency for evalffi
case consistency for evalffi
tstringinterp almost working
'discard' instead of 'nil' for system.nim
only 1 argument allowed for command expressions
case consistency for dynlib.nim
year 2014