Implemented vector connection extrema properties, linear scaling as explicit function in expression engine.
Parse src and dest extrema references as variables in expression engine; allocate memory for vector extrema.
Free destination ranges in connection.
Removing range property from connections.
Adapted testlinear program for new range datastructure.
Merge branch 'expressions' into vector-extrema2
Use mval union for storing connection ranges.
Remove superfluous casting
Merge branch 'master' into vector-extrema2
Revert addition of linear() function and range variables to expression engine.
Restored arguments for mapper_expr_evaluate().

And one more...
Added remaining connection props to flags; only attempt to set connection ranges if appropriate types and vector lengths are known.
Allocate memory for connection ranges when needed.
Corrected arguments for mapper_expr_evaluate()
Can't use memcpy for signal value -> mval union.
Fixed error-checking for boundary processing.
Fixed error-checking for setting linear expression.
Pass mapper_db_connection_t to mapper_msg_prepare_params()
Removing references to obsolete range property.
Python bindings: adapted typemaps for vector minima and maxima in db_connection struct.