These files differ on Windows and OS X.

Added a forgotten IDE to the .gitignore documentation.

Why?
For completeness and correctness

What?
[Webstorm](https://www.jetbrains.com/webstorm).

Since that is what it should be called now a days according to https://dev.twitter.com/fabric/android/integrating

which make it easier to find in search

JetBrains recently released a new C/C++ IDE: CLion

Intellij's iml file can be anywhere on the path.
This is true for multi-module maven project where each module has its own $projectName.iml file in its own directory.

These are relatively new, the crashlytics.properties file contains the secret and can [alternatively](https://plus.google.com/+AntonioBertucci/posts/S9krjvXfgfm) contain the apikey to rid your repo of the extra strings file.

Amends #1165

guess that root iml needs to be ignored and others need to be shared

removed the iml filter - this is my current best understanding of the docs, but I'm still unsure

To clarify when to ignore/include *.imls as per https://intellij-support.jetbrains.com/entries/23393067

also added optionals from the same

Fixes #1090 - this is the part of that PR that seems justified.

* Remove AndroidStudio.gitignore in favor of adding the
  change needed to the Global/JetBrains.gitignore file

Add plugin file description for JIRA config file containing username and password