projectile-kill-buffers: Ignore indirect buffers

When an indirect buffer is located after its base buffer in the buffers
list, `projectile-kill-buffers' gives an error ('No buffer named ...').
This commit filters out indirect buffers, which will be killed when the
base buffer is killed.
Merge pull request #360 from kyleam/fix-kill-buffers

projectile-kill-buffers: Ignore indirect buffers
Refill a docstring
Clarify a bit of code in projectile-kill-buffers
mentioned that persp-mode should be enabled to use persp-projectile
customize tags file
Merge pull request #362 from danielwuz/master

mentioned that persp-mode should be enabled to use persp-projectile
Merge pull request #357 from orikremer/customize_tags_file

Support custom tags file name
Try to use Projectile to find files in *compilation* buffer if possible.
If not, fallback to the original function.

* projectile.el (projectile-compilation-find-file): Use projectile to
find files in *compilation* buffer if possible.

(projectile-mode): Add the previous function around
`compilation-find-file'.

Add/Remove the advice around `compilation-find-file' when the mode is
on/off.
Merge pull request #363 from daimrod/compilation-find-file

Try to use Projectile to find files in *compilation* buffer if possible.
projectile-find-tag: Use ggtags-find-tag if bound
Merge pull request #366 from alanpearce/find-ggtags

projectile-find-tag: Use ggtags-find-tag if bound
* projectile.el (projectile-mode): Fix f71b5f7
Merge pull request #369 from daimrod/fix-compilation-find-file

* projectile.el (projectile-mode): Fix f71b5f7
[Fix #370] A temp workaround

advice-add and advice-remove are only available in Emacs 24.4.
Enable defining compilation/test commands in file-/dir-local vars.

They should be safe as long as they're strings.
Add Cargo.toml as a project root file
Merge pull request #373 from tomjakubowski/patch-1

Add Cargo.toml as a project root file
Add helm to allowable completion systems
Merge pull request #371 from immerrr/mark-cmds-safe-if-strings

Enable defining compilation/test commands in dir-local vars