reduce size of repository

I add this patch for anyone have do idempiere at 3.1 also 2.1 branch.
just clone current repository of idempiere. switch to 2.1 and apply this patch, you can materialize for 2.1 as before

note for eclipse user:
+ after materialize, have to refresh all project to make library bind to project.
(in headless and jenkins, buckminster always do a refresh workspace)

+ some time by network or file server (bitbucket, maven), download process break.
it don't break materialize process, so you still see all project loaded in eclipse, but can't build.
just re-materialize (can immediate run import/buckminster not need clear workspace)

Hi , I finish this job.
1. patch commit in https://bitbucket.org/idempiere/idempiere-experimental/ is all script to get library from outside of idempiere repository

2. you can get idempiere-experimental and run reduce process by yourself follow guide at "migration/reduce_repository/readme",
after that upload to https://bitbucket.org/idempiere/idempiere-reduce
or you create idempiere-reduce and let me right to upload
i putt my one for reference https://bitbucket.org/hieplq/idempiere-reduce

3. note:

• some library i can't find out same version as version in old repository, so i get near get version and i think it's compatibility.

• some library i can't find information about it, or it's too old to has a compatibility version in internet, with this case, i upload old jar to https://bitbucket.org/idempiere/idempiere-experimental/downloads and reuse

• for speed up materialize process, i don't download source of library

• some library useless, so i remove it.

4. what things i already test:

• build by eclipse: pass

• build by jenkins (my local jenkins): pass

• compare workspace of old repository and new repository

• some source file is loss (it's indent as note 3)

• some library is difference (it's indent as note 3)

5. what things maybe improve (it's issue of old repository not by reduce process)

• some library can't find out in internet, better replace by other library or remove it

• some library too old, event in beta version

• more library has osgi version, should use osgi version

• some project has reference not good, example zk library requirement adempiere.extend and re-use some library from adempiere.base

• duplicate library (can improve by put all necessary un-osgi library in targetPlatform or outside lib folder and other project use it).