Applying insserv patches upstream

[Jesse Smith]

This weekend I went through the Debian patches for insserv in order to
get as much material as possible upstream.

The following patches are now applied upstream:

20_manpage_spelling
21_tweak_warnings
30_interactive_regexp_match
92_m68k_alignment
100_show
130_crossbuild_fixes
150_core_string_test
160_manual_page_update
170_undeclared_extension
180_maxsymlinks

The rest appear to be Debian-specific configuration changes or build
flags which I'll leave to be applied downstream.

- Jesse