Some work on error underlining
Some work on error underlining

Still work in progress. Fixed ordering of line/column numbers.
Added request method. Still need to figure out idle timer, there
seems to be some kind of race condition.

rneatherway/FsAutoComplete,kjnilsson/FSharp.AutoComplete,cloudRoutine/FsAutoComplete,cloudRoutine/FsAutoComplete,vasily-kirichenko/FsAutoComplete