Fix #4333 (files shown as plain text incorretly).

- Added FileUtils.getBaseName (jsdoc and unit tests included).
- Replace usage of path-utils.js with getBaseName.
Fix unit tests for FileUtils.getBaseName.
Add support for project-wide JSLint config.

Related to issues #3269, #4210.
Based on the discussion and suggestions in #3310.

If a project has a .jslint.json in its root, it gets loaded and passed to each
JSLint run within the project. The configuration file gets reloaded each time
it is saved or refreshed.
Revert "Add support for project-wide JSLint config."

This reverts commit 11dbdfdb5d84ecaee826bd722b1053ede0fba60e.
Fix CSSUtils unit tests.

The tests assumed that CodeMirror modes are loaded at the time of test
definition.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/file/FileUtils.js
Fix Editor tests.

LanguageManager.getLanguageForPath should not use URLs. Instead, it
should use local filesystem paths.
Removed excessive : from the test description.
Add getFileExtension implementation and unit tests

Also:
Remove leftover reference to LanguageManager from FileUtils.
Use existing code to implement getBaseName.
Get rid of PathUtils where appropriate.

Implementation changed to use FileUtils.getBaseName and
FileUtils.getFilenameExtension.
Remove stale jslint PathUtils refs and extra loads
Restore jslint config to include PathUtils.
Fix code review issues.
Merge pull request #4379 from busykai/master

Fix #4333 (Files incorrectly identified as plain text if folder's name has got the "#" char)