- Some platforms don't expose kill() unless _POSIX_C_SOURCE is defined.
- fork(), execl(), and setsid() need unistd.h on some platforms.
Basically, this fixes some platform-specific build errors.
Fixes segfauls for any case where swaynag->outputs was not inititalized
including -h/--help, -v/--version, and invalid arguments.
Sets sane defaults for colors not given. Any color not given will
fallback to the default color values for type error.
Adds support for a hidpi cursor