Added text based edit item: In previous version only numbers could be entered as data field. This changes introduces a edit field for entering text in upper characters. '_' are used for seperation because simple white spaces (' ') would cause problems in the handling of the edit field. String length is limited to eigth charecters.

Imported from Ac6/SystemWorkbench/plugins/fr.ac6.mcu.firmware_1.14.7.201711101414/resources/builtin/:
* File syscalls.c