Update JetBrains.gitignore

Added a forgotten IDE to the .gitignore documentation.

Why?
For completeness and correctness

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

Update TeX.gitignore

Add a .gitignore for Unreal Engine 4

gitignore for laravel5 and lumen

In Laravel 5 the storage folder was moved to the root of the application. The compiled.php has also been moved to the bootstrap/cache directory

This was no longer compatible with the previous laravel.gitignore.

Fixed generated part js file pattern

Added some folders the are "compiled" things

Updates based on discussions with Dart team

/vendor - composer modules can be (and probably should) recompiled. Laravel comes with this line by default.
/node_modules - npm modules, same of /vendor.  Laravel comes with this line by default.

/app/storage - Laravel things that can be despised (in staging) like cache, views cache and sessions

1. Updates based on discussions with Dart team
See https://github.com/dart-lang/www.dartlang.org/issues/1496
* Removed *.precompiled.js - not generated by dart2js any more
* *.js_ → *.part.js

Also:

2. Added guidance comments

3. doc/ → doc/api as manually written documents may be in doc/

4. Added reference to appropriate Dart web site page

Some details for Castalia statistics file

Before XE7 Castalia used to be standalone expert thus I suppose here should be some grounding

Update Dart.gitignore

Add *.precompiled.js as per
https://stackoverflow.com/questions/20314796/which-files-are-generated-when-executing-dart2js-and-why

Modify patterns to explicitly match directories

Modified patterns to match files created by tool in Dart SDK 1.12:
 - Added patterns matching files listed in https://www.dartlang.org/tools/private-files.html
 - Added *.js, removed *.js_, *.dart.js to match files created by dart2js

Add /cover to Elixir.gitignore

Added fastlane to iOS projects

Ignore temp Hypothesis test things

added .env.example for projects generated with laravel new command

Ignoring build folder inside app module in Android projects

The `*/build` folder should be ignored because the android structure generate files and outputs inside this folder.

Add rule for MS PowerPoint temporary files