[gerber] Parser does not support multiple data blocks per line

[Juan Pablo Caram]

Gerber specifies that LF (line feed) and CR (carriage return) are only for visual purposes but are ignored, and each data block ends with the mandatory end-of-block character asterisk '*'.

FlatCAM is failing to parse lines like this:

G54D11*G36*
X8890Y61259D02*Y61595D01*

They are quite unusual, but GEDA PCB will still generate such format.

[Juan Pablo Caram]

Priority increased as it impacts user adoption.

[Juan Pablo Caram]

Fixed in 31ddb9c.