initial interface for C# SendGrid Mail library
initial unit tests for header
Modified Isendgrid to add new header object, and removed erroneous dependencies from files
Merge pull request #1 from sendgrid/us1882

Us1882
Added bin files to the gitignore so that they can be ignored
Added Sendgrid disabled apps methods. Will work on enabled apps methods. Also need to figure out how to write tests
added David McGuires implementation of the SMTP wrapper
Added Enable apps methods. Still need to validate certain functionality
Refactored the filters enum to be a key/val dictionary set, as the key and val names didn't match appropriately.
Also added validation. Now need to test.
header changed to property
return type for AsJson fixed
initial attempt to send message over REST interface
allow dependency injection of client, constructor is now in a factory method
new dependencies
empty doc stuff
flushed out the Sendgrid.cs file
attempted merge
updated...
includes links to new files for testing
new test file