Doc meaning of $(PERL)
Avoid uninit value warning in t/Liblist_Kid.t
Delete unused PM_TO_BLIB macro
Space-quote pm_to_blib args
Absolutise all typemaps because with deep-located typemaps, eg
"lib/XS/typemap", if xsubpp is called from top level with
    $(XSUBPP) ... -typemap "lib/XS/typemap" "lib/XS/Test.xs"
it says:
    Can't find lib/XS/type map in (fulldir)/lib/XS
because ExtUtils::ParseXS::process_file chdir's to .xs file's
location. This is the only way to get all specified typemaps used,
wherever located.
xs_obj_opt method adds -o to all $(CCCMD) commands to put .o next to .c
Eliminate && from Makefile recipes - totally unnecessary
Sort realclean files = diff-able Makefiles
RE with interpolated filename needs quotemeta
Make t/xs.t et al pluggable
Refactor dynamic_lib
Refactor dlsyms
Refactor dynamic_bs
Refactor xs_o and xs_c
Enable XSMULTI: multi *.xs under lib/ "just work"
Test, fix static build XS
t/xs.t even more pluggable with extra args to make calls
Break pure_all target into pure_nolink and linkext.
This allows breaking subdirs into subdirs_static and subdirs_dynamic.
This in turn allows building either static or dynamic when subdirs.
Add t/xs.t subdirsstatic to test.
Test, fix static XSMULTI
Minor tidyup in makeaperl