Remove unnecessary wording about negative ignore rules.

This commit adds a global ignore file for SlickEdit, a commercial editor.

SlickEdit will create the following files when the user sets up a workspace:

*.vpw       Workspace file. Contains a list of project files associated with
            the workspace.
*.vpj       Project file. Contains the project’s settings, including the list
            of source files.
*.vpwhist   Workspace history file for Windows. Contains user session
            information (list of open files, debugger breakpoints, etc.)
*.vpwhistu  Workspace history file for UNIX/Linux/MacOSX. (Same as above.)
*.vtg       Workspace tag file. Contains a database of source code symbols.

It is assumed that GitHub users will generally not want to store their
workspace and project files in a repository, so those files are ignored
globally.  However, those files do not contain user-specific data so they
could be stored in a repository and shared among developers if desired for
a particular project.  This can be done by adding rules like ’!*.vpw’ and
‘!*.vpj’ to the project’s .gitignore file.

The workspace history and tag files contain user-specific data, so they
should not be stored in a repository.

For more information, download the PDF user guide from:
http://www.slickedit.com/products/slickedit/product-documentation

Note: The user guide is 1400 pages long and over 13MB in size.

Searching for ‘vpwhist’ will lead to the section that discusses storing
these files in a repository.

Dolphin, the KDE file manager, writes specific directory configuration in .directory files.

* 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

The next version of Cloud9 will use a top-level .c9 folder in the workspace for settings and metadata.

which is ".target" directory.

Those belong in other ignore files.

Based on advice in the documentation at
http://www.sublimetext.com/docs/2/projects.html

From the documentation at http://docs.vagrantup.com/v2/getting-started/project_setup.html

"The Vagrantfile is meant to be committed to version control with your project, if you use version control. This way, every person working with that project can benefit from Vagrant without any upfront work."

The old pattern was too broad and was making VIM ignore Scheme (*.scm) files.
Now it only matches files that start with . or _.

Documented at http://docs.vagrantup.com/v2/getting-started/project_setup.html

These files are created automatically the first time a vagrant box is started.

As is clearly stated in the [eclipse documentation](http://wiki.eclipse.org/FAQ_How_do_I_set_up_a_Java_project_to_share_in_a_repository%3F).  
This gitignore has lead to much confusion in SO - please ammend

I would guess the same is true for .pydevproject and .cproject but can't
be sure/do not have any references on those

Also .launch configurations are generally meant to be versioned when
saved under project location. See for instance :
http://stackoverflow.com/a/337317/281545

https://github.com/mpeltonen/sbt-idea generates this folder

.*.s[a-w][a-z] matches named swap files.
.s[a-w][a-z] matches unnamed swap files.