* Fix some docstrings and one Print -> print.
* Fix test_{class,code,descrtut,dis,extcall,parser,popen,pkg,subprocess,syntax,traceback}.
These were the ones that generated code with a print statement.
In most remaining failing tests there's an issue with the soft space.
This was started by Mike Bland and completed by Guido
(with help from Neal).
This still needs a __future__ statement added;
Thomas is working on Michael's patch for that aspect.
There's a small amount of code cleanup and refactoring
in ast.c, compile.c and ceval.c (I fixed the lltrace
behavior when EXT_POP is used -- however I had to make
lltrace a static global).
* Can now test for basic blocks.
* Optimize inverted comparisions.
* Optimize unary_not followed by a conditional jump.
* Added a new opcode, NOP, to keep code size constant.
* Applied NOP to previous transformations where appropriate.
Note, the NOP would not be necessary if other functions were
added to re-target jump addresses and update the co_lnotab mapping.
That would yield slightly faster and cleaner bytecode at the
expense of optimizer simplicity and of keeping it decoupled
from the line-numbering structure.