Remove obsolete build order panel
Remove build order panel from addin config
Remove incorrect hint path
Remove Build order widget designer files
remove ALLOW_LANGUAGE_VERSION_PREFERENCE this hasnt been used for some time
Removed FSharpProjectParameters

The only purpose of this was to supply an alternative item order, we
now only support the build order in the project file as xbuild is used.
Removed FSharpProjectParameter instances

We now use the files list from the CompilerArguments.getSourceFiles
rather than the BuildOrder parameter of the FSharpProjectParameter
CreateProjectParameters now uses a standard ProjectParameters instance
Removed defunct function

This function is no longer used as we dont need to build ordered sets
and intersect.   The secondary functiob was to make the files relative
if the relative parameter was set, although that parameter is always
false in the current code.
Removed FSharpProjectParameters usage

We not just get the source files and wrap then with a simple map -
CompilerArguments.wrapFile
Merge pull request #261 from 7sharp9/remove_old_code

Remove some old code. Works for me.