scripts: Add migration wrapper script

This patch adds a migration wrapper script to workaround issues in
the bug2issue when it deals too many bugs at a time.
Usage of this script:
bug2issue_migrate.sh -e ../../bin/debug/bug2issue.exe \
  -sCLOSED -sRESOLVED -t -pACPICA -fbug_status -fresolution \
  -frep_platform -fop_sys -fpriority -fbug_severity \
  acpica/acpica acpica:password localhost:3306 bugzilla root:secret

Signed-off-by: Lv Zheng <lv.zheng@intel.com>