Configurable outline width and outline colors in highways and landusage

Replaced the static values for outline width of railway, other, track, tertiary, secondary, primary and pedestrian with variables defaulting to the old values in generate_style.py

Added configurable outline width and color for railway, industrial, residential and waterarea defaulting to the same color as the area and a width of 0 in generate_style.py

Thus more configuration options are available with an unchanged output.