bash script improvements

[detiber]

• bash_startup improvements (seeing a performance improvement of about 36ms in parsing the default.ftcommands, also removes external calls to sed)
  • use parameter substitution instead of splitting with the IFS when reading default.ftcommands
  • escape quotes using parameter substitution instead of sed
  • replace sed in trim with parameter substitution

[detiber]

updated to address feedback.

[p-e-w]

Merged! Thank you for your work. I have added your name to the about dialog credits.