Update ICU to a more recent version.

[mgautierfr]

Following https://github.com/openzim/javascript-libzim/issues/58 we have to update ICU to a more recent version.

ICU is a tricky part :

• We patch the ICU data to put "only what we need".
• To patch it, we need to use the svn version, not the released sources.
• We package differently the data depending of the platform.
• On android, it is the application itself which contains the data and load it for us before using libzim/libkiwix.

All those things was made on long time ago. We probably better have to question all of this instead of blindly do the same thing.

[kelson42]

From my side, requirements are:

• data should be available and loadable separatly (to avoid duplicates - one per arch - in Android bundle).
• data should be minimal to avoid waste of space/bandwidth
• Most use cases should have the data in the binaries
• We should do our best to avoid code patching

[kelson42]

Fixed by #642