Add equality/inequality operations for strings
Add equality/inequality operations for strings

Added all the equality (=) and inequality (<, >, !=, ...) operations for strings.
Now the AST is constructed in a correct way for all these operations.

Signed-off-by: Sebastiano Mariani <aede0281c92ed74ce106a06c39d2ff364ac8a785@gmail.com>

angr/claripy