[#52] Add zstyles to configure syntax-highlighting
[Fix #52] Add zstyles to configure history-substring-search
[Fix #419] Rewrite module gpg-agent; rename it to gpg
[Fix #426] Correct syntax error in variable assignment
Prepend $HOME/bin and $HOME/sbin to path by default
- Enable zsh functions 'zargs' 'zmv'
- Activate some handy modules by default