Feature/multi tab support

[Efratror]

Adds support for sketches with multiple files/tabs.

Description of the changes All the .pde files in a workspace are keyed by there filename with there contents as value in to a contents map. When a file changes, is added or removed the map is updated. When preprocessing starts each line of the contents map is added to a bigcode block. Each line number of the file/tab is keyed to the line number of the big code block. The big code block is then further preprocessed.

When a server request (definition, diagnostics or reference) is passed by the client. The line number of the big code is converted to the line number of the file/tab it belongs to.

Closes #28