added main.{c,h} files
added static shutdown function
added default config file path
added include for stdlib header
added missing includes
added missing LDFLAGS
trivial functions should be inlined
configuration parsing is called by core
binary goes to ./bin
reimplemented error checking

Each function can set a error function which gets called if the program is
forced to shutdown itself. This _on_error function should free() all remaining
memory.

This replaces the shutdown-function part in core, which is removed by this
commit.
Merge branch 'core' into add-main
rewrote main.c

Adapted to new and upcoming architecture.
started rewrite of core.c
Makefile ordered, clean task for op added
Merge branch 'add-main' into core
added compiletime macro for time.h and print.h headers
rewrote as we dont need this macro stuff
rewrote error handling

We don't need a that messy error handling. Just report an error, print it if the
config is set for verbosity, check if it is a fatal error, if yes -> shutdown.

Not more, not less.
adapted error_report_error() call to new prototype
Merge branch 'rework-errors' into rework