Getting stars via hacking the game config file

After you assemble the picture for the World 3, you can't get the second
star anymore, and you must re-start the game all over. The following lets you
fool the game into believing you got the star(s).

Each of the 8 stars is represented by a bit in the 25-th byte of the
config file. Steam/DRM-free Linux version of Braid keeps its config in
~/.Braid/slot_0.braid_campaign.

For example, if the hex dump of the first 32 bytes is:
00000000: 1c00 0000 9700 0000 ff00 0000 7d00 0000  ............}...
00000010: 7f00 0000 0600 0000 6a00 0000 0000 0000  ........j.......
then, after skipping 24 bytes, the "6a" (=0b01101010) is the stars byte.

Its bits meaning (dot represents zero):
MSB   LSB
...1 .... = World 2-2 Star (The Cloud Bridge)
1... .... = Hub Level Star (The House)
.1.. .... = World 4-5 Star (Movement by Degrees)
.... 1... = World 4-7 Star (Fickle Companion)
..1. .... = World 5-4 Star (Crossing the Gap)
.... ..1. = World 6-5 Star (Impassible Foliage)
.... .1.. = World 6-6 Star (Elevator Action)
.... ...1 = World 1-1 Star (Braid)

For example, set the byte to 0x90 (=0b10010000) for the first two
(inconvenient) stars. Or set it to 0xfe (=0b11111110 = first 7 stars) to
(re)play the final (princess) star level, with green-glowing switches.
Setting it 0xff also works as expected :)