Ignore doc/
Merge branch 'master' of git://github.com/Groogy/rbSFML

Conflicts:
	.gitignore
Merge branch 'master' into buildfix
Merge branch 'master' of git://github.com/Groogy/rbSFML
Merge branch 'master' into buildfix
Completely remove old lib/include build reqs

rbSFML can also be built on Windows without these directories, so they
serve no purpose. Made SFML_LIB and SFML_INCLUDE environment vars
optional.
Fix test/samples require paths for new SO_DIR
Simplify Windows build instructions, use rake gem
Merge pull request #46 from silverhammermba/buildfix

Update Windows instructions, gem path fixes