Fix unitialized pointer in elf
Initial work on the evaluable opcode analysis strings

- New command 'ae' to evaluate those expressions
- Use 'ao~code' to see the generated eval strings
- Rerefix udis86 16bit issue
Add 'pcw' and 'pcd' to print C code for 32 and 64 bits
Use r_file_abspath() and add dir.projects eval config var
Fix rarun2 stdout and stderr pipes

dcu requires argument to work
Enhace rarun2 manpage
Fix rax2 -B for negative values