Fixes several small issues found with PTS testing
Fixes several small issues found with PTS testing

1. BT clock reading is retried a few times upon failure. Temporary
   failures seem to be common (at least in a VM environment) and
   CSP needs to deal with it more gracefully.
2. Do not read local BT clock if ioctl() fails; fail and let the
   higher-level function to retry. No clock is better than the wrong
   one.
3. Add a field to SyncLeadTime in capabilities struct, since this
   is checked by PTS and a better/clearer estimate is needed
   throughout the code (see below).
4. Make sure every scheduling is delayed by SyncLeadTime. PTS does
   not like to receive a message before this.
5. Added a more conservative (and bigger) estimate of SyncLeadTime
   (PTS insists about receiving immediate responses within it).
6. Sync Indication is immediately sent in two ocasions: right after
   a sync set, and right after sync set response (and every "n"
   seconds after that, depending on required accuracy).
7. Timestamp resolution is set to 1 when operating system call
   yields resolution = 0.

silent-snowman/bluez,mapfau/bluez,pkarasev3/bluez,mapfau/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,silent-snowman/bluez,pkarasev3/bluez,silent-snowman/bluez,pkarasev3/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez