In apps_std_imp file build list of paths once without need of additional parsing

[quic-parihar]

recommendation came up is PR: #234

apps_std_imp.c file -> get_dirlist_from_env function.

First we concatenate the strings here, then you parse that during file open. Why? Can't you perform it exactly in the opposite way? Build the list of paths here only once, without additional parsing of the "resulting" string?
going through the string, looking for ; symbols, etc. That needs to happen only once, while you handle the environment variable. After that it should be a list of strings. The path that you got from the config file should be added to the list rather than being concatenated to the string.