Merge pull request #168 from lastland/master

Add "sbt compile" and "sbt test" to default compile and test commands of a sbt project.
[Fix #166] Add support for ag
Add django and python projects.
Merge pull request #169 from proofit404/python-support

Add django and python projects.
Fix Ag support
Merge pull request #170 from lunaryorn/fix-ag-support

Fix Ag support
[Fix #171] Don't cache ignored files
[Fix #173] Ignore some buffers depending on the major mode used

Add a custom variable to ignore some buffers when they are a major
mode. A list of regular expressions is used to identify the major
modes to be ignored. The current list is quite arbitrary.
Merge pull request #174 from vincentbernat/feature/ignored-modes

[Fix #173] Ignore some buffers depending on the major mode used
[Fix #172] Add an option to purge files/subtrees from cache
Fix a typo in `projectile-cache-current-file'
Fix integration build
Remove ert dep
Use the EMACS env variable value if available
Use Cask 0.5.0
Fix build
[Fix #176] Opened files added to the cache as if belonging to the root directory

Variable 'current-file' was refering to the file basename in function
projectile-cache-current-file.

It now refers to the relative path of the file from the project root directory.
Merge pull request #179 from jnnh/fix-opened-file-basename-added-to-the-cache

[Fix #176] Opened files added to the cache as if belonging to the root
Use canonical unittest runner for python projects.
Add prefix file name search together with suffices.
Toggle between test and implementation now work for django and python project.
Ignore 'build' directory as very parasite for search in python projects.