Allow empty String values to be read in XML tags. E.g. <default></default> will read a value of "" instead of considering this an error.
Check for non-empty tag values read after allowing GetString to return empty values
[fix] settings loading of default value for CSettingPath: parent class CSettingString already handles it
Merge pull request #3043 from Voyager1/xml-empty-stringvalues

Allow empty String values to be read in XML tags