GitLab

In preparation for unicode support.

This will allow roughly the same behavior as Python3 for non-ASCII strings,
for example, print("<phrase in non-Latin script>".split()) will print list
of words, not weird hex dump (like Python2 behaves). (Of course, that it
will print list of words, if there're "words" in that phrase at all, separated
by ASCII-compatible whitespace; that surely won't apply to every human
language in existence).

This behaviour follows Python 3.5 standard (in 3.4 it's a
DeprecationWarning which we'd rather make a TypeError).

Some small fixed:

- Combine 'x' and 'X' cases in str format code.

- Remove trailing spaces from some lines.

- Make exception messages consistently begin with lower case (then
needed to change those in objarray and objtuple so the same
constant string data could be used).

- Fix bug with exception message having %c instead of %%c.

Also, make sure that args to "*" format specifiers are bounds-checked
properly and don't lead for segfaults in case of mismatch.

Once a double quote has been found, the subsequent discovery of a single quote
won't change behaviour at all, so don't bother looking for one.

This way, it's slightly more efficient, uses less ROM (60 bytes less
for stmhal), and doesn't require to raise exception if bad operation
given.

This renames:
MICROPY_PY_FROZENSET -> MICROPY_PY_BUILTINS_FROZENSET
MICROPY_PY_PROPERTY -> MICROPY_PY_BUILTINS_PROPERTY
MICROPY_PY_SLICE -> MICROPY_PY_BUILTINS_SLICE
MICROPY_ENABLE_FLOAT -> MICROPY_PY_BUILTINS_FLOAT

See issue #35 for discussion.

Reorder interning logic in mp_obj_new_str, to be more efficient.

str_new is globally accessible, so should be prefixed with mp_obj_.

This removes need for some casts (at least, more than it adds need
for new casts!).

Older int-only encoding is not expressive enough to support arbitrary slice
assignment operations.

Now of the form MICROPY_PY_*.  See issue #35.

See issue #608 for justification.

Done in generalized manner, allowing any stream class to be specified as
working with bytes.

sep=None is TODO.