Set master for 2.5 development mode
Add a script for making releases
Merge branch '2.4'
Merge branch '2.4'
Merge branch '2.4'
Merge branch '2.4'
Merge branch '2.4'
Merge branch '2.4'
Merge branch '2.4'
Merge branch '2.4'
Make it possible to forward declare struct json_t

This allows e.g. to use json_t in a header file that doesn't include
jansson.h:

    struct json_t;
    typedef struct json_t json_t;

    json_t *foo(json_t *bar);
Merge branch '2.4'
Compress bz2 doc tarballs with bzip2 instead of gzip

Fixes #99.
Enable gcc specific flags in tests correctly

... and fix issues found.
Don't use -Werror by default

It may be problematic when compilers add new warnings over time.
./configure && make should always just work.
Merge branch '2.4'
Enable -Werror in Travis builds
Merge branch '2.4'
check-exports test: Filter out symbols that start with an underscore

These are usually internal to libc, and such symbols are exported in
the shared library on some platforms.
Merge branch '2.4'