Fixed drv_serial inline function declarations (fail at least with crossworks compiler)
Restored previous version, but remove inline declaration in drv_serial.c to avoid linker errors
Fixing software serial inversion.  RX inversion was not implemented in
the new software serial receive implementation and TX was ignored
because the 'isInverted' flag was never set.
Merge pull request #56 from hydra/software-serial-fix-inversion

Fixing software serial inversion.
Rename telemetry.c to telemetry_frsky.c in preparation for adding
another telemetry provider
Cleanup telemetry code.  Remove duplicate logic.  Improve readability.
Add support for another provider.  Change default softserial baud rate
to match the speed used by FrSky telemetry.
Allow user to use telemetry on softserial port 2.  Should have been in
previous commit.
Move common telemetry code to telemetry_common.c/.h
Removed unused variables.

Compiler warning were generated when compiling using GCC with
-Wunused-variable
Enable HoTT as a telemetry provider.

Import cGiensen's HoTT telemetry implementation - untested.
Improve HoTT code readability.  Add protocol overview comments.
Improving code readability by aligning comments with code and removing
comments that duplicated code.  Comments are harder to refactor than
code and become stale.  Updating default and limit values for some
settings to use enum values.
Adding author information and linking to original source for some of the
HoTT code - https://github.com/cGiesen/MultiHoTT-Module
Removed needless memory copy operation.  Removed checksum bytes from
HoTT packet structures, checksum is always sent by the response sending
code.  Reduce ram usage by 173+ bytes.  Corrected accreditations.
Updating documentation to match code.  Replaced comments that commented
out code with #ifdef blocks because commented out code is not found by
refactoring tools.
Move port telemetry port configuration logic into common telemetry code.
Update software serial to support RX, TX or RX&TX modes.  Update serial
API to allow on-the-fly changing of serial port mode.  Update HoTT to
change serial port mode when transmitting.
Fixing software serial stop bits.  Was broken since timer frequency
calculation changes in c7de7d2ebc63ae02c598f19e7af3b9673feaae62.
Merge pull request #58 from hydra/softserial-fix-stop-bits

Fixing software serial stop bits.
Update timer handling to support multiple events at the same time.

This can occur when servicing two software serial ports via a multiple
timer channels on the same channel.
Avoid softserial loopback on port 2 on Olimexino boards.
Ignore incoming software serial data that doesn't have a start and stop
bit.  Track software serial transmission and receive errors.
  
Nothing exposes the error counter values yet.