Add padding sections.

See merge request allzp/zipr!6

Add padding sections to a zipr'd program where
the gap between two existing sections is greater
than a certain minimum boundary.

Make a global PAGE_SIZE definition.

See merge request allzp/zipr!4

Fix typo in ElfWriter::DetectMaxAddr

See merge request allzp/zipr!2

Resolve "unpinned ibts result in pins"

Closes #3

See merge request allzp/zipr!1

Removed bea engine from lots of inclue places and link steps, changed verbose mode for zipr to false, added very-verbose mode for zipr.  fixed a few zipr bugs related to non-existant fallthroughs, etc.