Changes to support un-attended operation.
Changes to support un-attended operation.

fsck data disk once if mount throws an error.
--create "once|always|never" - try to control when a new vhd is created - not quite working except for 'always'
--teardown "pass|fail|always" - when to teardown the vm and re-mount the data disk to copy logs
--prompt "no" - prevent 'press enter'

the local logs are now copied to locallog/<testname>_pass|_fail/

karataliu/WALinuxAgent,jerickso/WALinuxAgent,ryanmiao/WALinuxAgent,yuezh/WALinuxAgent,hglkrijger/WALinuxAgent,AbelHu/WALinuxAgent,fieryorc/WALinuxAgent,yuezh/WALinuxAgent,imikushin/WALinuxAgent,hglkrijger/WALinuxAgent,ryanmiao/WALinuxAgent,Azure/WALinuxAgent,imikushin/WALinuxAgent,SuperScottz/WALinuxAgent,rjschwei/WALinuxAgent,andyliuliming/WALinuxAgent,lizzha/WALinuxAgent,AbelHu/WALinuxAgent,jerickso/WALinuxAgent,Azure/WALinuxAgent,thomas1206/WALinuxAgent,lizzha/WALinuxAgent,karataliu/WALinuxAgent,rjschwei/WALinuxAgent,nathanleclaire/WALinuxAgent,fieryorc/WALinuxAgent,nathanleclaire/WALinuxAgent,thomas1206/WALinuxAgent,SuperScottz/WALinuxAgent,andyliuliming/WALinuxAgent