Auto-rule for INSTALL_DATAS and cbits/ header files:
Nuke $(shell perl -e '...') use, i.e., don't load in and start up
a 3M binary just to capitalise a word (which gets done twice per
invocation of 'make').
ifeq "$(IS_CBITS_LIB)" "YES"
override datadir:=$(libdir)/include
-INSTALL_DATAS += Hs$(shell perl -e 'print ucfirst "$(PACKAGE)"').h
else
SRC_CC_OPTS += -Icbits
endif