#137 Make all our standard examples work when executed with wish_standard_examples.sh

[Alan W. Irwin]

Examples 2, 14, 20, 24, and 31 do not work properly when executed under wish using the package require command to set everything up so they are currently commented out in examples/tk/wish_standard_examples.sh.in due to various issues that have been documented in that file. For example, both examples 2 and 24 used to give errors concerning colour maps, but they now just segfault on Linux. These issues do not exist for the corresponding plserver execution of all our standard examples using examples/tk/plserver_standard_examples.sh.in. The differences between the two cases are relatively small so in theory it should be straightforward to figure out and fix what is causing the problems for the wish_standard_examples.sh case.