Per new conventions, we'd like to consistently use "u*" naming conventions
for modules which don't offer complete CPython compatibility, while offer
subset or similar API.
Also provides setraw() function from "tty" module (which in CPython is
implemented in Python). The idea here is that 95% of "termios" module usage
is to set raw mode to allow access to normal serial devices. Then, instead
of exporting gazillion termios symbols, it's better to implement it in C,
and export minimal number of symbols (mostly baud rates and drain values).
stat() is bad function to use using FFI, because its ABI is largely private.
To start with, Glibc .so doesn't even have "stat" symbol. Then, layout of
struct stat is too implementation-dependent. So, introduce _os to deal
with stat() and other similar cases.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
This is to reduce ROM usage. stream_p is used in file and socket types
only (at the moment), so seems a good idea to make the protocol
functions a pointer instead of the actual structure.
It saves 308 bytes of ROM in the stmhal/ port, 928 in unix/.
Each built-in exception is now a type, with base type BaseException.
C exceptions are created by passing a pointer to the exception type to
make an instance of. When raising an exception from the VM, an
instance is created automatically if an exception type is raised (as
opposed to an exception instance).
Exception matching (RT_BINARY_OP_EXCEPTION_MATCH) is now proper.
Handling of parse error changed to match new exceptions.
mp_const_type renamed to mp_type_type for consistency.
Ultimately all static strings should be qstr. This entry in the type
structure is only used for printing error messages (to tell the type of
the bad argument), and printing objects that don't supply a .print method.
It's no longer intended to provide just "raw" socket interface, may include
some convenience methods for compatibility with CPython socket - but anyway
just minimal set required to deal with socket client and servers, not wider
network functionality.
