GCS:Removed unused variables and typedef
GCS:Initialize variables to supress warnings
GCS:Use Q_UNUSED macro on unused parameters
GCS:Add -Wno-sign_compare compiler flag to qwt and utils libs

This supresses warnings and was preferred to fixing the issues since
they are external libraries and best kept in sync with authors.
GCS: Config plugin removed invalid slot connection
GCS gpsdisplay:Added stdint.h to fix compilation
GCS Map:Changed scope of contextmenu object, it was duplicating on each show
GCS Map:Fixed size of pathplanner dialog

It was showing as a minimal widget