(Most of it isn't used yet, but at least it's stored.)

Uncomment now-implemented functions; allow general 'layout' setting.
Drop 'locked' option for autolayout (handle this automatically)
Allow general layout 'style'.
Add font setting

Alignments can (eventually) only have a single fixed node in them, and after they're run, those nodes then count as 'fixed'.

Needs more defaults, but works with SBMLNetwork's base defaults.
Also, update to SBMLNetwork's latest API.
Also also, don't worry about individual lines, with their start/end/midpoints.

… into add-layout-render

(We need it for SBMLNetwork)

Sprintf has been getting warnings for years; replace with stringstreams.

The "{" and "}" characters are actually already unique; I don't need to also check for the preceeding "\".

signed/unsigned issues; double/int issues.  Fixing the latter now acutally allows defining algebraic rules with doubles, not just ints.

* It's now 'layout' that's on/off, not 'autolayout'.
* X and Y are now set properly instead of to NaN.
* More often export size if height or width is different.
* Check valid color values.
* Allow different capitalizations of layout keywords.

* Better handling of NaNs (ignore them more often)
* Convert colors back to HTML names if necessary.
* Check unset elements better.

Mostly better handling of group defaults.

Use new 'autorender' so we don't call autolayout twice.

Both have memory leak updates, and SBMLNetwork has efficiency updates.

The default is now changed in SBMLNetwork, so we need to set it explicitly here so we don't re-call the autolayout algorithm all the time.

Also, clear out some unused comments.

The functions now allow you to deal with alias nodes.  This is a first pass at that, that doesn't actually deal with alias nodes in the slightest, but at least continues to compile with the new version of the library.

* Parse strings with less copy/paste of bison code.
* Fix error typo.
* Disallow negative sizes.
* Turn on layout with fewer cues.
* Add layout/render tests.