Minor cleanup

Deleted *.wtch files, xm16.inc.  Added *.zip to .gitignore.
Incremental commit for working changes from i2ctask

srtxuser.inc - change task 3 from 5 sec to 2 sec (so fails faster)
  also remove IF AD_COMPLETE_TASK == SCHEDULE_TASK (etc.) options
strc.asm - disable interrupts in trace
srtx.asm, sisd.asm - remove IF AD_COMPLETE_TASK == SCHEDULE_TASK (etc.) options
2nd incremental commit

si2c.asm, sisd.asm, srtx.asm, susr.asm, susr.inc
  rename SUSR_TaskI2C to SUSR_ISR_I2
susr.asm - remove SUSR_UdataSec
strc.inc - Added STRC_ISR_BEG_I2C and STRC_ISR_END_I2C
3rd incremental, this one successful

blah.lkr - removed SUSR_UdataSec
srtx.asm - SRTX_Dispatcher can invoke SUSR_TaskI2C.
susr.asm - SUSR_TaskI2C invokes UI2C_MsgTC74ProcessData.
  changed all smTrace to smTraceL
ui2c.inc - Add UI2C_MsgTC74ProcessData.
ui2c.asm - UI2C_Tbl_MsgState goes to UI2C_MsgTC74Complete not UI2C_MsgTC74ProcessData.
  new UI2C_MsgTC74Complete copies msg data and incrs SRTX_Sched_Cnt_TaskI2C.
sisd.asm, strc.asm -  cosmetic.
Docs updated for moving I2C temperature processing into scheduled task.

User Manual updated, along with Visio doc and resultant .wmf files
.gitignore - removed refs to .vsd, .wmf, and .jpg so those now tracked
Added .vsd, .wmf, and .jpg files to repository
Update readme.txt to include contents in .zip archive