man: store shadow man pages in git rather than generating them

Simplify the build process and the makefile.

Local fix in CVS for bug 5628 is not required
as the problem has been fixed in
util-macros d9062e4077ebfd0985baf8418f3d0f111b9ddbba

Signed-off-by: Gaetan Nadon <memsize@videotron.ca>