allow for custom bash prompt
Look for a custom bash_prompt file before copying

We'll remove the default bash_prompt in the next commit and rely
on individual configurations to provide this.
Remove default bash_prompt file, this is a custom option

Fixes #302
Add config/bash_prompt to gitignore
Update CHANGELOG to reflect bash_prompt addition
Switch to chris-lea/node.js PPA for up-to-date node/npm versions
Have npm install itself to ensure latest version
Update CHANGELOG and Contributors list

Fixes #408, #406
updated php error_log location to shared folder
updated php error_log location to shared folder

Maps to /srv/log, which is a shared folder in VVV's log/ directory
Introduce the general log directory for storing log files
Log files should be ignored once created
Mount the shared log directory with www-data as owner
Update CHANGELOG, logs directory README
Document code style guidelines in CONTRIBUTING for shell and PHP

Fixes #195
Merge branch 'docs/style-guide'
Make the README.md newbie (me-bie) first.

* Re-organized README so each section first speaks to theme and plugin
developers, the largest audiences, the audiences that benefit from a
little hand up.
* Introduced users to the shared filesystem.
* Tighted some of the language.
Keep the mission statement the same (for now)

Keep the 3 sentence/paragraph structure - wording changes ok
Be more explicit about WP directory locations in VVV

It may not be obvious that these directories are located in the
www directory of VVV
We haven't yet introduced `vagrant-local` as a concept

It may not make sense in the README quite yet. That said, the
getting started may move up in a bit here.c