Add daemon function to start daemon simply.

I will be switched daemon process or normal process with argument.
Add parseForegroundCommandLineArgument function.

This function return true when "--foreground" is included in argument.
And I will create switchDaemon function to switch daemon process.
Add switchDaemon function to switch daemon Process.
Remove unwated call daemon function.
Add 'static' qualifier.
Change order to parse.
Add testMain file to test src/main.cc

First step, I have added include files and licence display.
Fix typo.

errorno.h -> errno.h
Change function name.

parseForegroundCommandLineArgument -> isForegroundOptionIncluded
switchDaemon -> Daemonize
Change function name.

Daemonize -> daemonize
Because othe functions in Hatohol begin from lower case.
Add include file glib.h