Log Message:
Changes 4.4.3:
* NEW Implement pan and zoom via mouse wheel.
* NEW set key maxcolumns N maxrows M
* NEW value("varname") returns the value of the named variable
* NEW encoding cp1251 - 8-bit Cyrillic
* CHANGE backport emf terminal driver from version 4.5
* FIX better estimation of latex string lengths
* FIX colorbar representation of discrete color palettes is pixel accurate
* FIX NaN initialization and tests working on more (all?) platforms
* FIX configuration script tests for readline+ncurses
* FIX prevent out-of-range boxes from creating degenerate ghosts on the border
* FIX missing alpha channel flag for pdfcairo terminal
* FIX font initialization in windows terminal