Change Json Serializer in VfsStatEntry to use lower case.
This makes it inline with the format C9 uses
(https://github.com/c9/vfs-http-adapter)

Fixes #587
DropboxHelper should ignore .git and .hg folders at any level
Fixes #586
Add http headers to env.aspx
Simple scripts and custom webpi feed to automate devbox setup.
Tweaked readme to fix some typos and improve clarity.
Make the test cache repository a bit more resilient against partial clones

Fixes #589