Refactor language server transport code

[glennsarti]

With #188 merged we need to refactor the TCP and STDIO code.

1. The namespace of PuppetVSCode isn't really true as the code in there is agnostic of IDE and relates to language server only; i.e. It's not just VSCode

2. The code in (GH-#187) Add a stdio mode to the language server #188 uses a blocking form of IO. This cannot be taken advantage of in the debugserver as it has to be non-blocking. I punted on this when I first wrote the debugserver and I used TCP instead. Need to refactor the transport layer;

• All the transport layer does is send and receive text from the JSON handler. The API should reflect this
• The STDIO code should be moved out of the Puppet Language server and moved into the shared location for the debug server
• The STDIO transport needs to be rewritten to be non-blocking
• Need to solidify the object used between the JSON handler and transport layer (TCP or STDIO)
• Need to run the CI tests in AppVeyor and Travis for cross platform testing.

Relates to #187

[glennsarti]

Solved in puppetlabs/puppet-editor-services#9