Merge branch '0.3.4-fix-headers-601'
Fix regexp treatment of alias addresses

Currently a regexp is created for every alias in configuration file. However
special characters are not escaped which causes a mismatch. Mail aliases are
string literals that may contain lots of special regexp chars and those
should be escaped before compiling a regexp.

Changed 'determine_sender' function to escape aliases before compiling
regexp.
Merge branch '0.3.4-fix-aliases-614' into testing