OP-1198 allow GCS gadgets to store/restore individual state (needed for OP-1194)
OP-1194 scope gadget will now persistent plot and legend visibility state between runs

+review OPReview
OP-1194 minor cleanups to scope gadget state persistence handling
OP-1233 added make options to skip qmake and build single gcs dir
- add QMAKE_SKIP=1 on make command line to skip qmake
- add MAKE_DIR=<dir relative to ./ground/openpilotgcs> to compile that directoy only
- example : make gcs QMAKE_SKIP=1 MAKE_DIR=src/plugins/coreplugin
- use at your own risks ;)

+review OPReview
OP-1026 Add a task monitor api to calculate idle percentage
OP-1026 replace idle time calculation with task monitor API
OP-1026 remove legacy idle time calculation in OPLink code
OP-1243 fixed duplicate popup menu entries appearing when opening menu multiple times
- also removed two unconventional Close menu entries
- and other minor cleanups

+review OPReview
OP-1026 fix review issues
Make WriteFile use Events to signal when write requests are
finished. This avoids lockups on Windows platforms during hid_write. (see OP-1261)
Merge remote-tracking branch 'origin/next' into filnet/OP-1243_opmap_widget_duplicate_popup_menu_entries
Merge branch 'filnet/OP-1243_opmap_widget_duplicate_popup_menu_entries' into next
Merge remote-tracking branch 'origin/next' into filnet/OP-1194_persist_scope_gadget_plot_and_legend_visibility_state
OP-1194 uncrustified
Merge branch 'filnet/OP-1194_persist_scope_gadget_plot_and_legend_visibility_state' into next
Merge branch 'filnet/OP-1233_add_make_options_to_skip_qmake_and_build_single_gcs_dir' into next
OP-1233 documented new GCS make options (QMAKE_SKIP and MAKE_DIR)
Merge remote-tracking branch 'origin/D-Lite/OP-1261-winHIDfix' into next
Merge branch 'amorale/OP-1026_cpu_idle' into next
OP-1233 fixed parallel build regression introduced when splitting openpilotgcs target into _make and _qmake
both _make and _qmake would wrongly run in parallel when using -j2 or similar option