Added some <see> tags

Added some <see> tags to the documentation comments, and added a CDATA
where it was necessary but not used.
Add optimization for ImmutableList<T>.AddRange when adding non-empty range
to non-empty list
Apply same optimization for ImmutableList<T>.InsertRange, also add more
  test coverage
Update Developers.md

Fixing the name of and adding a link to Visual Studio Community 2013.
Documentation comments: CDATA to {T} for generics

Replaced CDATA with {T} syntax for generics in documentation comments.
Make InsertRange rebalance list correctly
Change Node.Root to internal to facilitate testing
Revert changes to InsertRangeTest
Add more tests
Update Developers.md

Visual Studio Community and Visual Studio 2015 Preview text and links
Update Developers.md

Add text and links for Visual Studio Community and Visual Studio 2015 Preview.
Merge branch 'patch-1' of https://github.com/jac009/corefx
Add doc comment for BalanceNode method
Add license header to test source files.
Add ImmutableArrayExtensions.SelectMany extension method
Optimized ImmutableArrayExtensions.SelectMany method for a zero-length source array.
Merge branch 'master' of https://github.com/ProgramFOX/corefx
Added AppVeyor CI script

Fixes #48
Added build status badge to README.md
Move developer guide to wiki

Updated links in README.md and CONTRIBUTING.md to point to wiki.

Deleted docs/Developer.md as the content has been merged to the
wiki.

Also, changed some markdown links to end-note style for better
word wrapping.
Moved some variable declarations that were defined in an outer scope

Removed whitespace
Merge branch 'master' of https://github.com/n1ghtmare/corefx
Add reference equality check to SetEquals methods.

The SetEquals methods are rather expensive, and it's a quick and super-effective check to compare reference equality between the two collections before engaging in the expensive work.