Don't use install to copy header and library files to avoid having them
Update license date on all files. No functional changes.
Include license updates in more directories; improve directory descent
in root Makefile to avoid errors and loops.
Include INSTALLFLAGS in install targets in Makefiles.
Add man page for llogger. Makefile repairs for llogger (didn't have
dependencies quite right).
Add util directory for utilities only marginally related to the GDP.
The first entry is llogger, which is kind of like logger(1) but it logs
to local files instead of syslog. It is intended to timestamp debugging
output from gdplogd and gdp_router_click.