drop Python 2.3 support

[jek]

• update docs
• pick through list comprehensions and convert to generators as appropriate
• flip decorator usage in lib/ to @syntax
• clean out util and compat

[Mike Bayer]

what version ?

[jek]

i had been thinking that 0.5 would be the last with 2.3 support, but now i'm leaning toward 0.4.

0.5 is going to have to support 2.6 and people will want to 2to3 it. i see 2.3 support as adding unneeded pain to that process.

[jek]

Processed started with 6917ffb9bdae19a368abef5fdbd4655fc27fcdf2; no longer source compatible with 2.3.

Internal functions which accept lists need to be inspected across the board & evaluated for accepting generators instead. (We should do this for functions at the user/API edges, regardless of 2.3)

[jek]

grunt work: 8fa48edbf9d84093152aced94fc1eb7996b9827f 1d37472fdd1e4091fe2d158a21b27043fc8626f9 8b12c8f1c2048a9ef6f19b66823bf6053efff565 4eb747b61f0c1b1c25bdee3856d7195d10a0c227 4f56fd23bcd6c0adc11138fa50249095c7d4dd73 acbfb9ea2b78b97800356e8dec2c977e54447182 901d76beba05f0131602b747f2e656adc4451860

[jek]

some more in f893bb0b513e8e27403da55da0d68e3b15a13629.

moving to 0.5.x- this is far enough along for 0.5.0. remaining 2.3 decorator usage can just be flipped as it's noticed. (by anyone)

[Mike Bayer]

Removing milestone: 0.5.0 (automated comment)