Separate the API between cached/uncached methods

[patacca]

To avoid issues with cached/uncached objects below the function level (basic blocks, instructions, ....) it's better to have two separate APIs.

Ex:

p = ProgramBinExport("/path/to/file")
for f in p.values():
    for b in f.blocks:
        # do stuff
    for b in f.blocks: # cached object
        # do stuff

p = ProgramBinExport("/path/to/file")
for f in p.values():
    for b in f.uncached_blocks:
        # do stuff
    for b in f.uncached_blocks: # uncached object
        # do stuff

The user must ensure to never mix the cached and uncached behavior to avoid possible issues.

[patacca]

This PR is based on top of #4