The "ignored" variable type

[whisperity]

The original version had the ability for users to epc set-type VAR ignored which made Envprobe throw a fatal exception if the user wanted to access the variable in any way.

Related documentation code from the previous version:

    epilogue += "\nSetting the type to 'ignored' will make Envprobe "       \
                "prohibit access of the variable. (Note: this is not the "  \
                "same as \"track ignoring\" the variable. The latter only " \
                "disables the variable in the save/load command, the "      \
                "'ignored' type disables the get/set too!)"