fix code style.

both spaces and tabs are used for indentation in different parts of the code base. i think it's better to be consistent with mongrel2's code style, which uses 4 spaces for indentation.
remove unnecessary includes.
Merge remote-tracking branch 'github-yep/master' into yep-changes
Merge remote-tracking branch 'github-yep/fix-whitespace' into yep-changes

Conflicts:
	lib/m2pp.cpp
	lib/m2pp.hpp
	lib/m2pp_internal.hpp
	lib/utils.cpp
allow compile flags spec in environment

Conflicts:
	Makefile
add OPTFLAGS

Conflicts:
	Makefile
imp OPTFLAGS
Merge branch 'github-pjstevns'