Bazel: export LICENSE.txt file.

Signed-off-by: Piotr Sikora <piotrsikora@google.com>

Add inline allocation of bytes fields

This commit adds a new FT_INLINE allocation type that forces bytes
fields to be inlined into the struct. E.g., pb_byte_t my_bytes[32].
This requires max_size for the bytes field. The FT_INLINE type is
represented as a new LTYPE: FT_LTYPE_FIXED_LENGTH_BYTES.

This commit also updates the documentation with FT_INLINE and
FT_LTYPE_FIXED_LENGTH_BYTES.

Added an AUTHORS file in apparent order of appearance in the git log
history from $(git log --all).

Add bazel BUILD file for nanopb.

Fix suggested by Ulenspiegel.

Also added testcase for the same.

Fixes a potential security issue (#205). Only relevant if the user
code writes untrusted data to _count fields, but this is allowed as
per the security model.

Attempt at reproducing issue #204.

The FieldMaxSize class was reusing the same list instance,
causing problems when multiple files were specified on the
protoc command line.

Added explanation of `oneof` section usage

Update API reference to match headers

Update typedefs and function prototypes in the API reference to match
header files. Delete documentation for pb_skip_varint/pb_skip_string,
which are superseded by pb_skip_field, and add pb_get_encoded_size.

Generate MIN/MAX/ARRAYSIZE for enums

Add -D option to specify output directory

This generates #defines mirroring the following values from the generated C++ code of GPB
* const Foo Foo_MIN: the smallest valid value of the enum (VALUE_A in the example).
* const Foo Foo_MAX: the largest valid value of the enum (VALUE_C in the example).
* const Foo Foo_ARRAYSIZE: always defined as Foo_MAX + 1.

This is now handled automatically using shift operations.