Made the CairoPainter object a private variable to the class again instead of a local var in WriteMolecule(). I got errors when trying to depict multiple molecules otherwise.
Made hash bonds draw with line width 1, required adding the function GetPenWidth to the different painters to be able to reset the pen width after drawing the bond.
Added the -b and -B options to pngformat to allow changes of colors when creating pngs.
Added -xm option for possibility to "crop" output image to a close bounding box of a single molecule.
Changed the metrics calculation in cairopainter to give nicer layout of text labels with sub and superscripts.
Appended .md to README
CIF output wraps fractional coordinates to [0, 1]

Some crystallographic software with weaker CIF parsers will error if
atoms are not in [0, 1].

Also, whitespace edits. Tabs and trailing whitespace are bad.
Improved duplicate atom testing in `OBUnitCell::FillUnitCell`

Previous implementation was O(N^2), checking the distances of atom-atom
combinations. It regained speed by only checking atoms against their
symmetric counterparts.

This implementation is amortized O(N), using a hash function. It uses
the extra speed to check every atom-atom connection, which handles a
series of corner-case issues (e.g. input cif file having duplicate
atoms, mirrored symmetry expansions).

Note that this could be improved even further, but it would require
some heavier edits to openbabel. The best approach uses an octree, of
which there are existing implementations.
Added atomic number to FillUnitCell hash method
Aesthetic spacing alignment edit to CIF

Replaced "    %3s  %3s  %10.5f %10.5f %10.5f %10.3f\n" with "
%-8s%-5s%.5f%10.5f%10.5f%8.3f\n", ensuring everything stays aligned.
Fixed OBMol::Center segfault issue

There were two different implementations, and one was dependent on
private variables that didn't necessarily exist. Now there is only one
implementation, and it's the one that doesn't segfault.
Some cppcheck cleaning
Increase maximum number of atoms for an InChI to 65536.
Merge branch 'master' of github.com:openbabel/openbabel
Merge branch 'master' of github.com:openbabel/openbabel
Merge pull request #31 from serval2412/master

Some cppcheck cleaning
Merge pull request #23 from patrickfuller/master

Improvements to `OBUnitCell::FillUnitCell` and CIF writing
Merge pull request #19 from fredrikw/viz

Png depiction changes