userguide.adoc: edit for grammar, spelling and phrasing
userguide.adoc: simplify step 1 instructions (copying files to Saved Games\DCS)
userguide.adoc: remove Prolog section

The section referred to additional documentation that does not yet exist,
so I removed it for now.
userguide.adoc: edit for technical accuracy
Merge pull request #28 from jboecker/userguide-edits

User Guide edits
fix links in README
developerguide.adoc: add AsciiDoc attributes (TOC, icons, imagesdir)
developerguide.adoc: fix integer decode example
developerguide.adoc: fix math in explanation

The synchronization sequence used to be 0x55 0x55 0xff 0xff,
which is where the 65535 came from.
Merge pull request #30 from jboecker/developerguide-edits

Developer Guide updates
A-10C: fix categories of some controls

- FLAP_POS
- GEAR_HORN_SILENCE
- FLAPS_SWITCH
- TISL_MODE
- TISL_SLANT_RANGE
- LAMP_TEST_BTN
- SAI_CAGE
- SAI_PITCH_TRIM
- UHF_FUNCTION
A-10C: fix altimeter pressure controls
A-10C: remove redundant string outputs and fix alitmeter pressure controls
A-10C: fix swapped normal/tenths for engine temperature and core speed
A-10C: Add missing gauges and indicators

- Oxygen pressure, flow, volume
- Cabin pressure altitude
- DVADR "End of Tape" and "Record" lights
A-10C: add digital clock export, change CMSP line length to 19
Merge pull request #31 from jboecker/a10c-fixes

A-10C fixes (this changes most of the output addresses)