New structure for jars in zip package

Similar to 
http://code.google.com/p/google-http-java-client/issues/detail?id=109.

Summary by yanivi:

Currently the google-http-client jars are at the root of the zip file, and the 
dependency jars are in the dependencies folder.

Instead, I propose a new structure which puts all of the binary jars in a 
"libs" folder and all of the source jars are in the "libs-sources" folder.  No 
distinction between http base lib or the dependencies.  This follows exactly 
the structure of the jars in tasks-android-sample.

One motivation is that for Android applications, the package manager requires 
the directory with all binary jars to be called "libs".  Similarly, for HTTP 
servlets to jars must go in the war/WEB-INF/lib folder.  Normally source jars 
aren't placed in this directory, so that's why I recommend also doing the same 
for libs-sources.

Additionally, we should provide the classpath entries to use for the .classpath 
file for Eclipse for the various platforms.  It's just too much of a pain to 
craft them manually, and often people forget the sourcepath which makes it more 
difficult for debugging.

We should make the same changes in the projects that we own that depend on this 
project (api, oauth, etc).

Original issue reported on code.google.com by rmis...@google.com on 14 May 2012 at 3:00

fer626 / google-api-java-client

New structure for jars in zip package #487