Added JSON encoding.
fixed some subtle type errors
adding python driver support for R_JSON
fixing copy-paste typo in python driver
adding R_JSON support to the js driver
Merge branch '1571_json_protocol' into next
Make version more explicit in osx package

Review 1030 by @mglukhovsky
Closes #1413
Lowered LBA_READ_BUFFER_SIZE
Optimization of progress_app::handle() by using a shared pointer for the directory.

Conflicts:

	src/clustering/administration/http/progress_app.cc
Merge branch 'daniel_lower_lba_read_buffer_size' into next
Merge branch 'daniel_1660' into next
Merge branch 'next' into daniel_directory_efficiency

Conflicts:
	src/clustering/administration/http/progress_app.cc