Remove old data files and ignore bak folders
New base data files
Update fig:F-vs-U with new data
Update fig:Prop-foliage with new data
Update fig:Vogel-E with new data
Fix xtic spacing for fig:Vogel-E
Tidy gnuplot files
Update Notation section
JA2.2 Empirical n-VR curves
JA3.1 Add flexible keyword
JA2.2 Friction factor
JA2.9 Drag coefficient dependent on morphology
JA4.4 Surface waves and eddies
JA4.1 Justification of extreme velocities
JA4.3 Justification of fully submerged trees
JA5.1 Trees discarded once sign of decay
Add bending stiffness table and simplify table captions
Add more Vogel exponent context
Introduce Jarvela's X-value
Re-write paper overview and other general modifications