OPAC JS combation and compression enhancements

OPAC JS combation and compression enhancements

Added ability to combine locale-independent common JS files
(opac/common/js/) into a single JS file to reduce http back/forth from
the browser.  In the default skin, this combines 10 scripts into 1.  The
scripts to combine are parsed from js_common.xml (enclosed by START/END
COMPRESSION comments).  The combined file is created by autogen.  Use of
the combined file is enabled via new Apache configuration (off by
default).  When a JS compressor is configured in autogen, the JS file
will be subsequently compressed.

Also includes better IDL2js loader for My Account, which loads
additional fieldmapper classes.

TODO:
Add ./configure param for setting a JS compressor at build time
Options for providing compressed versions of other JS files

git-svn-id: svn://svn.open-ils.org/ILS/trunk@18905 dcc99617-32d9-48b4-a31d-7c20da2025e4