Fix #71 - correct regenerate tags keybinding in the README
Show indexing message only when doing native project indexing
Fix #60 - add the ability to manually cache files

Files are now also added to the cache automatically the first time
you visit them (via the `find-file-hook`).
Directories listed in .projectile file are excluded when tags are generated
Added comment to projectile-tags-exclude-patterns function
Merge pull request #73 from alexey-naydenov/tags_exclude

Regenerate tags function excludes directories listed in .projectile file