Tell Grunt/jshint to ignore `src/bp-forums/bbpress/`.

This folder is only present on SVN checkouts, but for people trying to contribute to BP using SVN, jshint was failing when it was trying to parse the old bundled version of bbPress.

See #6015


git-svn-id: https://buddypress.svn.wordpress.org/trunk@9146 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
bp-legacy: update RTL CSS.

See r9143 and #5513.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@9147 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Build: move list of ignored JS files from the Grunt configuration into the `.jshintignore` file.

The list of ignored JS files in the Grunt configuration was only used by the jshint task, so let's move these into the recently-introduced (r9146) jshint ignore file.

See #6015

git-svn-id: https://buddypress.svn.wordpress.org/trunk@9148 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Build: fix Grunt build-release/commit on SVN checkouts.

Old bbPress, which is a SVN external, was not being accounted for in the tasks' working directories/files.
This was causing most of our Grunt build commands to fail when run on a SVN checkout.

Fixes #6015


git-svn-id: https://buddypress.svn.wordpress.org/trunk@9149 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Build: have Travis-CI shallow clone the repo.

The Travis-CI clone depth default is currently 50. Reducing this might help speed up the tests as we don't need the extra history.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@9150 cdf35c40-ae34-48e0-9cc9-0c9da1808c22