Add configuration. See #5 #8.

What's new:
- --config flag to pass a INI config file to parse. See config.ini.
- Updated the modules scripts for configuration. Now needs to unset
  variables passed by CLI or config.
- Fix release directory that was added in love file (maybe).
- Properly escapes sed arguments.
- chmod +x to getopt.sh and read_ini.sh
- Fix #12

love-release.1

@@ -131,6 +131,11 @@ Set the version of your package.
 .B \-\-clean
 Clean the cache located in \fI~/.cache/love-release\fR.
 One can replace the Love files there.
+.TP
+.B \-\-config \fIfile\fR
+Pass a configuration file as argument.
+It describes which build you want to make, with what options.
+See \fIconfig.ini\fR.
 .SH MODULES
 The script is modular.
 Each different platform is handled by a subscript stored in \fIscripts\fR.