Blank lines in config file cause failures

[jmcphers]

If the config file contains a blank line, an error is thrown and the configuration is not used. This seems to be because the parser expects every line to follow the prevPage ... / nextPage ... format, and if it doesn't the configuration is considered invalid.

I've twice broken my config by accidentally leaving a blank line in the file and had to dig through the syslogs to realize what's wrong. It'd be great if the parser ignored blank lines (and ideally comment lines too!)