Add wall time tiers and more wall time exit code

[gongyixiao]

1. Add wall time tiers parameters to support different SLA setting on juno
2. Due to fixed bam truncation bug by using beforeScript and catch_USR2 #767 , this temporary solution for BAM truncation gives exit code 0 or 1 when USR2 was caught due to hitting the LSF time limit. So params.wallTimeExitCode is introduced to include 140, 0 and 1 all as valid wall time limit exit code to trigger the bump up of the wall time tier when retry.

[anoronh4]

changes made sense and test on small data set ran without issues.

[stevekm]

I am testing it as well though my dataset is large so its takes a while to finish, however, it does look good so far and I cant see any errors coming up. Thanks so much this is great :)