Fixing issue #171 - plus some cleanup tasks

Fixing System.ArgumentOutOfRangeException: Non-negative number required.

The biggest issue was fixed by switching to an unbuffered stream when
receiving a pack.  We also set the flag to bypass the httpRuntime
maxRequestLength, theoretically allowing upload of a pack of any size.

Also fixed various other issues related to large repos.  Git seems to
have a bug that although it's running a 32-bit executable, it detects a
64-bit system and uses the 64-bit config values.  This causes the
process to run out of memory when compressing large sets of objects.
This was resolved by adding a git config file in App_Data and updating
the code to provide the HOME environment variable to the Git process.
The values in the config file are reasonable defaults that allow cloning
of a 22GB repo without any issues.

Also fixed the maxAllowedContentLength to be 100MB to match the
maxRequestLength.  This doesn't seem to be used on IIS8, but the
previous 4MB value was way too small.

Various cleanup tasks in touched files:  putting using inside namespace
(http://stackoverflow.com/questions/125319/should-using-statements-be-inside-or-outside-the-namespace),
making lines more uniform.
Attempting to check in the Git config to be used on the server.
Reverting usage of "this" in files
Moved using statements back out of the namespace to be consistent with all the other files
Adding .gitconfig to the project

Forgot to add the .gitconfig file to the project.
Adding back missing using statements

These statements were removed because in Debug a section of code doesn't
exist and wasn't considered.  Verified with Release and Debug builds.
Added a Readme.md field for Repositories for a readme page using Markdown

Very similar to the readme.md page for github pages. For each repository
there is a new Readme property that is a string of markdown text that
describes the repository.  This could be used to describe the
dependencies, instructions and other information about the repository.
Added the MarkdownDeep nuget package to handle the transformation of
markdown text to Html.  The user interface includes a markdown toolbar,
help section and preview fields.
Merge pull request #178 from kfarnung/master

Fix for #171
Reverted previous implementation of the readme.md. Instead when using the repo browser any .md file will be rendered in the resulting markdown formatted text using the MarkdownDeep library.  This will allow a more general handling of markdown files inside a repository and is a much simpler implementation.
Added detection of markdown files and rendering when using the repository browser. Reverted old readme sql script.
Merge pull request #180 from kengibous/master

Added a Readme.md field for Repositories for a readme page using Markdow...
Version 3.4.2
Changelog format fixed