Revert "SDL: make the default NO_SDL"

This reverts commit 63d1d5457a4e6dd96782ede4bd84035be927fc51.
Added dirty mode to telemetry throttled mode. When receiving an update
during the throttled period, the UAVO is marked as dirty. The dirty object
will be sent once the period times out. This ensures that the latest copy
of a UAVO will always be sent, no matter when the UAVO was updated.
HISTORY.txt - various updates over the last few months

This is far from comprehensive and people should feel free to further
expand it.
README.md update text

No need to start by focusing on the fork.  We have moved beyond that.
Moved THROTTLED_DIRTY bitmask into enum. Fixed some code-style issues.
Merge pull request #511 from kubark42/telemetry-throttle-fix

Added dirty mode to telemetry throttled mode.
Created TreeItem class method for assigning m_currentTime. This simplifies
the number of required constructors.
all pios_spi: added non freertos handling of claim and release
all pios_spi: astyle format run
all pios_spi: fixed potential deadlock in non freertos mode
Revert "Merge pull request #533 from peabody124/hitl_fix"

This reverts commit 0b43e26c866a22fd8fe1472b960403d6283ea902, reversing
changes made to d7706af2f6bebb56b63d7fbb858435a9dab6937e.
Merge pull request #555 from lilvinz/revert_533

Revert "Merge pull request #533 from peabody124/hitl_fix"
Doxygen: update the module documentation
More module documentation updates
Modules: delete unused magbaro module

Work on #556
Modules: delete unused MKSerial module

Work on #556
Modules: remove unused OsdEtStd module

Used to work for eagletree but the format was undocumented and this
broke.

Fixes #556
Libraries: doxygen header updates

Sorry a few line ending conversions slipped in too
UAVObjectTemplate: update documentation
Doxygen: clean up the outputs