add missing imports
wrap initializers in functions.

the ugly global is a hint that the current setup (either the `global` keyword, or the global code for loading definitions and data) is not the best idea.
imho we should refactor this. simply import the module should not have this sort of side-effects.
offer ways to reload the nodefunction
wire in frontend
fix the `fixme`s

introduced to have data-compatibility after renaming the source_node and target_node parameters ages ago, this can be safely removed
checks and defeses against incompatible data

Don't break everything if the user gives us invalid nodenet data (nodes with no nodetype, links from wrong gates to wrong slots, etc)
fix err.message
fix shape-default
don't set `gen` when setting node activation

instead offer a set_gate_activation that will call report_gate_activation
remove forcing gen-links to gen-slots.

so that we can link gen to whatever we want
with node activation, set first gate activation?
string checksum instead of simple float sum
Merge pull request #17 from Doik/reload_data_functionality

Merging reloading of native module functionality