Documentation outdated for `printline()`

[btalb]

Commit 4251e79 seems to have added the strline() function for getting string representations as a replacement for printline(file=None).

Documentation for SE3 still suggests printline() will output a string when supplied with file=None:

Documentation for the new strline() function also doesn't seem to have been built.

[jhavl]

Thanks for noticing that, the docs seem to be out of date on Github pages. I'll get those rebuilt with the next pip release

[petercorke]

I've changed this stuff a lot, used to be all done by printline. Are these the right primitives?

[btalb]

I haven't noticed a strong convention in the Python community for "making print flexible enough to meet user needs". There's the extendable custom string formatting, but that looks like it may be a deep rabbit hole.

If it was me, my approach would be maximise flexibility for users by minimising work done here:

1. Have a single function that provides all possible "thing to string" conversion functionality
2. Make something like NumPy's set_printoptions() to support changing the default string representation globally / in contexts using with (optional)
3. Drop all support for sending the strings to files, and let users handle that through more generic Python methods available

With the flexibility of maybe swapping out 1 with custom string formatting if you feel the need in the future.