M2 migrations

String, Unstandard, Log, Random and Regexp have all been migrated to M2.

This means:

* M2 builds added, Ant builds removed.
* No longer can produce old servlet versions, everything is jsp
2.0/servlet 2.4 currently. Probably worth a global update to 2.1/2.5
later and maybe putting the version in the parent pom.
* Examples wars not being built.
* Doc wars won't be built anymore - replaced by Maven Taglib plugin.
* Added to Continuum (vmbuild.apache.org)
* Likely to break in Gump as I don't know what I'm doing there.

TODO:

* Migrate others - Datetime, JNDI, i18n, RDC, Standard, Iterator.
* Replace examples with unit testing (Cactus? Probably as Standard
will want this).
* Include taglib docs in download.
* Include tld in download.
* Create M2 based parent site. Very tempted not to have subsites, but
to link the top site in directly given that I've always wanted to do
that.
* Delete old build system once all are done.
* Update Regexp to JDK Regexp instead of ORO.

If anyone wants to claim a particular task, or has other ones that
need doing, feel free to pipe up.

Hen