Feature(amend): Commit message formatter script support

[ashelly]

Topic: commit_message_format_script
relative: relative_topic_takes_topic
Label: draft

[ashelly]

Reviews in this chain:
└#2 Feature: revup completion for bash
　└#1 Feature: revup edit
　　└#6 Feature: Revup Edit saftey features to help prevent accidental stack corruption
　　　└#3 Feature: Revup commit gains --topic and --relative to pre-populate commit message
　　　　└#4 Feature: Revup commit gains --draft flag
　　　　　└#7 feat(amend): enhance --relative to accept explicit topic
　　　　　　└#8 Feature(amend): Commit message formatter script support

[ashelly]

#	head	base	diff	date	summary
0	38ee5ed4	9e230aa4	diff	Jan 30 16:23 PM	4 files changed, 565 insertions(+), 3 deletions(-)