Modular status bar for dwm written in c.

The statusbar is made from text output from commandline programs. Blocks are added and removed by editing the config.h file.

I modified some code for the sake of my needs, such as mpd status, network speed indicator. I used to use shell scripts for generate some info, but i decided to wirite C snippet with some C api for dissatisfaction with some lack of info.For expmple, i need to wash version of low bitrate songs, mpc status cannot show current playing's bitrate, though it doesn't make much sense for others. At least i can learn some C code, LOL.

Source code is modified from Suckless.org dwmblocks.

Description below is extracted from LukeSmithxyx's github READMEA:

Most statusbars constantly rerun every script every several seconds to update.
This is an option here, but a superior choice is giving your module a signal
that you can signal to it to update on a relevant event, rather than having it
rerun idly.

For example, the audio module has the update signal 10 by default.  Thus,
running `pkill -RTMIN+10 dwmblocks` will update it.
You can also run `kill -44 $(pidof dwmblocks)` which will have the same effect,
but is faster.  Just add 34 to your typical signal number.
My volume module *never* updates on its own, instead I have this command run
along side my volume shortcuts in dwm to only update it when relevant.

Note that all modules must have different signal numbers.

I add a func pointer in last of block's sctruct so it can run c func in plugin folder.