Split oLschema2ldif into library and binary

Split oLschema2ldif into library and binary

The oLschema2ldif program was contained in a single file, making reuse
of its parsing logic elsewhere impossible. With this change the majority
of the code is moved to a new file, "lib.c", while the CLI interface is
now in a "main.c" file.

End-of-line whitespace is also removed.

Signed-off-by: Michael Hanselmann <public@hansmi.ch>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>