cleanup addon binary build

The binary build assembly has several things to clean up.

• copying top level release-notes over those in src/main/readme (not currently an issue because there is no release-notes at the top level)
• LICENSE/NOTICE is not an aggregate of component's binary form versions of these, nor is it a reference to them.
• stanzas copying src/main/scripts and src/main/properties, both of which are non-existent directories
• stanzas copying target/site/apidocs of various kinds, which don't exist
• the assembly is done even when the -Papache-release is not active. (All our other builds only build the assembly when this is active; some files, such as issues fixed, are only available to be included when this profile is active).
• the technique used to include the additional support directories for binary packaing, is to copy the files from the ones used to prepare the PEAR packaging. This includes some PEAR-specific files, in particular the metadata/install.xml, which should not be part of the non-PEAR assembly binary package.