LDAP.pm: UTF8-decode the LDAP error message
LDAP.pm: add an option to ignore some error codes
Lib.pm: also enable debug for other systems
add `devel/verbose` (wrapper to set debugging envvars)
Revert "Lib.pm: also enable debug for other systems"

This reverts commit 269a2006a1e1d6fd4e909e0f14472218a7a71220.
Lib.pm: handle SIGUSR2 for toggling $::debug
lib.bash: early stages of proper file namespacing