- Avoid to stumble on bug in QtCore.pc on older distributions

- Refresh patches to see in which C function each change is in
- Reenable bitmap terminals

- Update to gnuplot 4.6.0
* New syntax supporting multi-line blocks of code delimited by curly braces
if () { ... } else { ... }
do for [] { ... }
while () { ... }
* Time formats can handle fractional seconds to microsecond precision.
* User-definable linetypes that can be used to establish a locally
preferred default sequence of colors or dash/thickness/point styles.
* Statistical summary of the data to be plotted (new command "stats")
* New terminal drivers: qt context epscairo cairolatex
* The version for Windows received major improvements
(GUI, help, native terminal and wxt, installer)
* Improved support for UTF-8, SJIS and other multi-byte encodings