Move sourcing of development.sh to GDB_AC_COMMON

Move sourcing of development.sh to GDB_AC_COMMON

The same is done for gdb, gdbserver and gdbsupport.  I therefore think
it makes sense to move that to GDB_AC_COMMON.

It is required to move the call to GDB_AC_COMMON so it is before
GDB_AC_SELFTEST in gdbserver/configure.ac, otherwise the $development
variable isn't set when the code behind GDB_AC_SELFTEST executes.

gdb/ChangeLog:

	* configure.ac: Don't source bfd/development.sh.
	* selftest.m4: Modify comment.
	* configure: Re-generate.

gdbserver/ChangeLog:

	* configure.ac: Don't source bfd/development.sh, move
	GDB_AC_COMMON higher.
	* configure: Re-generate.

gdbsupport/ChangeLog:

	* configure.ac: Don't source bfd/development.sh.
	* common.m4: Source bfd/development.sh.
	* configure: Re-generate.