Merge pull request #33 from groessler/something_to_pull

em-test.c: add support for Atari
Fixed some return pointers.

$1234 pointers were returned as $3434.
Merge pull request #34 from greg-king5/lower-upper

Fixed 2 string-function return-pointers.
Bumped driver api versions due to recent intoduction of library references.
Added more details about how the CBM exec() works.
Merge pull request #35 from greg-king5/cbm-chain

Added more comments to CBM exec().
Don't shift in an unknown carry bit.

If that bit happenned to be set, then it would defeat the fancy ADC shifter.
Added a cbm510 lightpen driver.

It's similar to the current c64 and c128 lightpen drivers.
Made mousetest.c know that the CBM510 has a lightpen driver.
Merge pull request #36 from greg-king5/cbm2

Fixed a small bug in a joystick-mouse driver.
Renamed the CBM510 lightpen driver to include the 184-C pen.
Merge pull request #37 from greg-king5/lightpen

CBM510 lightpen driver
Fix strtoul 'endptr' return value: It should point to the first invalid character,
not to the last valid character.