Add action to delete projects from helm-projectile-switch-project

It's annoying to delete projects one by one. This action is added to
solve that problem.
Basic support of Rust’s Cargo projects
Merge pull request #476 from vhbit/rust-cargo

Basic support of Rust’s Cargo projects
Merge pull request #475 from tuhdo/master

Add action to delete projects from helm-projectile-switch-project
Add helm-projectile-find-file-in-known-projects

Also refactor projectile-find-file-in-known-projects and separate code
that returns files in all projects into a function for reusability.
Merge pull request #477 from tuhdo/master

Add helm-projectile-find-file-in-known-projects
Update README and CHANGELOG
Merge pull request #481 from tuhdo/master

Update README and CHANGELOG
Fix erroneous call to non-existent function
Merge pull request #482 from tuhdo/master

Fix erroneous call to non-existent function
Merge pull request #474 from YorkZ/helm-switch-project

Performance optimization and eliminate boilerplate code
Change key binding compile project action

C-c is common prefix that should be reserved for users. We should bind
compile action to something else, like M-c.
Remove an extra space
Update the MELPA urls
Fix error when Projectile fails to get sub-project files

When external command for getting sub-project files fails, it should not
break Projectile. Simply fall back to the default behavior.
Merge pull request #484 from tuhdo/master

Change key binding compile project action, fix external command error and add new action to create virtual directory
Add melpa badges
gittip is now gratipay
Add ?r command to commander

?r calls projectile-replace
Merge pull request #494 from syl20bnr/add_r_to_commander

Add ?r command to commander