[zshdb] zshdb release around the Ides of March

[Rocky B. <ro...@gn...>]

I am currently planning a release around March 15, the ides of March.

Changes include:

 - Updates for bash 4.2
 - syntax coloring if  the Python pygments package installed (and
--highlight option used)
 - easy way to evaluate the current source line or expression inside the
source line (debugger commands "eval" and "eval?")
 - ability to go into a nested shell but keeping existing variables  and
functions set. (debugger command "shell")  With this, one needs...
 - ability to save variables to an outer shell  ("set_vars" function inside
the interactive shell)
 - ability to save values from inside a subshell  to the outer shell
(debugger command "export")

Haven't done this yet, but nested debugging of expressions. Previously I
allowed only file names and
I wasn't setting variables properly there.