Merge branch 'master' into tmp

Conflicts:
	crant
Merge pull request #19 from krlmlr/tmp

use temporary directory instead of hard-coded name
Merge pull request #21 from krlmlr/clever-bump

Various enhancements for bumping version (-u switch)
Merge pull request #22 from krlmlr/compact-vignettes

compact vignettes
Merge branch 'master' into develop

Conflicts:
	crant