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