HPCC-9629 New language features to support bundles

Add evaluate mode to ECL compiler (to extract bundle information) and various
flags to allow bundles to be parsed without picking up extraneous files.

Option to suppress logging by eclcc (otherwise sudo ecl bundle install
tends to leavelocked logfiles around...)

Fix trivial memory leak in file hook plugins.

Add ecl-bundle program for bundle file manipulation

Add BundleBase to Std library, and provide an example bundle
implementation.

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>