emacs: Fix a warning

Fix a following byte-compile warning:
ninja-mode.el:18:7:Warning: assignment to free variable `ninja-keywords'
emacs: Place provide form at end of file

Any errors in the code after "provide" will leave the feature
registered, so it should always be at the end.
Merge branch 'fix-warning' of git://github.com/yasuyk/ninja

Conflicts:
	misc/ninja-mode.el
Merge branch 'fix-provide-form' of git://github.com/yasuyk/ninja

Conflicts:
	misc/ninja-mode.el