JPS ProjectSettingsImpl: read custom compiler options and plugins
(cherry picked from commit 3b7948f)
ScalaCompilerSettings: process -Xplugin options
(cherry picked from commit c4d0698)
SBT project import: display "SBT" instead of "SBT project"
(cherry picked from commit 82d5cae)
Project conversion: use only "safe" chars in library file name
(cherry picked from commit 75381a1)
SBT settings placed in "Build Tools"
Scala settings placed in "Languages"