Only respond to QUIT messages that have a matching username to the
logged in user, instead of any QUIT messsage

- Adds proper handling of server QUIT messages
- Exits with a non-standard exit-code on a QUIT or dead connection

Updates the cleanSplit function to not initialize a potentially
wrong-size slice which will contain empty strings.

Includes some minor formatting changes

The config file parser wasn't stripping the lines before
splitting them on ',' which resulted in empty strings in
the list of matches, which apparently match every string.

Also fixes a typo in a log statement. All ignore channels
*must* have the prefix ('#') in front of them, so adding
that to the log statement was redundant and inaccurate.

Adds the ability to exclude channels and specific users (nicks, not
usernames) from triggering a notification. These are specified in the
config as a comma-separated list, and each entry is checked for each
message.

Matches were changed to a list. Also specified as a comman-separated
list, each entry is checked.

Adds REST call to Pushover API to send notifications when matched phrase
is received from the network.

Configuration via POSIX getopt-style flags and an optional key-value
configuration file. If specified, the settings in the file are read
first, then overwritten with the commandline flags. This means that the
commandline flags take precedence over the configuration file.