Fix #1691 - Add comments, xrefs and flags in pdj

jump lines should be done in the client side. all the
information required to do the lines is in this json.
Fix #1694 - Fix dcs after ds
Implement emacs keybindings for Visual mode (thanks jonatanhal)
Fix rpnesil ',' (nop) continuation issues
Handle emacs keys ^f and ^b in dietline too
Fix linker flags issue on darwin, when USE_RPATH=1
sys: change vala and valabind script to use PREFIX variable in CONFIG
Honor `sys` path detection
Fix win32 build on CI
Verify that the sdb files in syscall/d are created
Implement Regex ROP search in the /R/ command:

Contains the following commits:
- make rop search a regular expression
- fix indent and some variable decl places
- remove some debug comment stuff
- make regexp not compile for empty rop search
- change from r_search to r_regex for ropsearch
- make /R/ the option for regex rop search
- make the regex outside of the loop
fix crash in rop issue #1711
Fix 'bad C' in ioplug->debug
Add JSON support to the PDB parser
Finally remove the void*debug pointer from RIOPlugin (use bool isdbg)
Fix reverse RGB parser (fixes ecj issues)
Fix CID 1238665 and 1241777 aka memory leak and out of bounds write in flirt
Handle names in 'dm' for OSX/iOS
Fix #1667 - Fix --with-syszip
fix leaks in rop search