Merge branch 'feature/build-lib-gitsubmodule' of github.com:exxcellent/echo3

This introduces a Git submodule reference which provides all required
3rd party libraries to compile Echo and adjusts the default build
properties accordingly.

Resolved conflicts in ant.properties and did some minor corrections.
Change version to 3.0.1-SNAPSHOT.
Fixed minor defects in the IDEA project

The YUI compressor library is no longer required/present.
Added some notes about starting development using IDEA & Ant.
Merge branch 'feature/idea-project' into 3.0.x

Provide a default IntelliJ IDEA IDE project.
For best results use the commercial ultimate edition,
but the community edition works fine as well an misses
only selected features.
Merge remote-tracking branch 'remotes/official/3.0.x' into exxcellent

Resolved conflicts:
	.gitmodules
	ant.properties