Update Elixir.gitignore

Add yarn ignored file

elisp: add emacs backup files and undo-tree save-history files

Update to take into account Dart SDK 1.20

Add rule to unignore the maven wrapper jar

[Android] Add .idea/tasks.xml

Updated Jetbrains.gitignore

Delete IPythonNotebook.gitignore

Add .dir-locals.el

Read more here: https://www.gnu.org/software/emacs/manual/html_node/emacs/Directory-Variables.html

The IPython Notebook is now known as the Jupyter Notebook (see http://ipython.org/notebook.html). Jupyter ignore values are already found in the Python.gitignore.

Update of Visual Studio gitignore file.

TeX: feynMF/feynMP

add the *.VC.db to unreal engine ignore

as of visual studio 2015 update 2 this file stores the intellisense database.
this file is typically huge and shouldn't be included in a repository.

If the .gitignore file is inlcuded in another project, it may be feasible to have a reference to origin.

Reference: http://stackoverflow.com/questions/1826901/should-i-add-vcxproj-filter-files-to-source-control

Dart SDK 1.20 no longer creates `packages` directories. Added comments to `pub` files section to differentiate  what is needed for >= SDK 1.20 and what is additionally needed for older SDK versions.

The Objective-C and Swift gitignore files are missing `*.xccheckout`
and `*.xcscmblueprint`, but these are still included in the Xcode
gitignore. This commit synchronises the three files.

The files themselves contain information about the user's local
source control status and shouldn't be included in most Xcode
repositories.

`*.xcuserstate` appears to always be contained in `xcuserdata/`
which is already ignored.

Added datasource folder

Use the exact CC-0 license text

Rename 'IPython Notebook' comment to 'Jupyter Notebook'

Nanoc: Fix capitalisation + config filename

Update ExtJs.gitignore

Please refer to [the official guide](https://intellij-support.jetbrains.com/hc/en-us/articles/206544839-How-to-manage-projects-under-Version-Control-Systems).

ignore Visual Studio 6 workspace file

see e.g.
http://stackoverflow.com/a/1530193
https://msdn.microsoft.com/en-us/library/aa241721(v=vs.60).aspx

Removed LaunchSettings.json from being committed

ignore public/storage for laravel 5

Ref: https://github.com/laravel/laravel/blob/master/.gitignore#L2

Update/opencart

This should really ignore compiled .beam files as well