removed static declarations from (external) header jsonrpc-c.h

these declarations yield warnings in every C file that includes jsonrpc-c
(except for jsonrpc-c.c itself)
Merge pull request #9 from metratec/master

reentrant cJSON parsing and various fixes: allow reliable cJSON stream p...
Merge branch 'master' of github.com:hmng/jsonrpc-c
Merge branch 'master' into debianize