On-demand loading of meta info

[tecimovic]

Zap is currently doing the following wrong thing:
1.) When starting up, you specify the ZCL and generation meta-info files.
2.) Zap will physically load those two bits of data into the database upon startup.
3.) When we load the .zap file, it will attach to these.

This model completely breaks-down when we load in the multiple .zap files that are based on different SDK.

The required flow is the following:
1.) We specify ZCL and generation meta-file at startup but those are just DEFAULT values.
2.) We do NOT load them at startup.
3.) When we open a "new configuration", we only then load in the DEFAULT metafiles, unless previously loaded.
4.) When we are loading in a .zap file, we take the values of the meta-file from the .zap files and:
a.) we load them in at this point, if not yet loaded.
b.) if we can't load them, we ask the user if it's ok to use DEFAULTS.
c.) user may also choose to point to a whole-different set of files which we load in at this point.