Build with lens<4.

This fixes up changeset 7f3ed3166913133cb0f97d89356b4ff7ee8531fb with a modicum of ugliness.
Merge pull request #26 from DougBurke/patch

- Fix behavior of rlabel with VTA_BaseLine.
- Many changes to make code compatible with -Wall
Docs: remove mention of Cairo; clean ups and additions.
Docs: remove mention of Cairo
Merge pull request #29 from DougBurke/patch

Doc changes (Cairo+clean up)
Adjust lens constraint to allow v4.1.*; update package versions to 1.2.2
BUGFIX: textDrawRect

The bounding-box calculation had the Y axis reversed, so the box was below the label. I have left in a commented-out version of drawTextA which adds in the bounding box, since there are differences between PNG/Cairo and SVG/Diagrams output, e.g. test8, which looks like a SVG rendering issue but I have not looked into it too deeply (you also see this difference in the misc1* tests).
Polar: initial attempt to iterate on the plot position given the label size.

This does not actually do any iteration of the calculation due to a bug in textDrawRect.
Merge from origin/master
Merge remote-tracking branch 'origin/patch' into polar