Annotation blank lines

Using SV 0.9 (still :-) in Windows.

Blank lines in text annotation files generate spurious data.

For example, when there is a blank line at the end
of a text annotation file, an extra time instant
is added to the layer at time 0. The label of
that time instant is related (but not the same as)
the last non-blank time-instant data line.

For example:

32.328 111|40|-269
32.638 112|-36|273
32.878 113|48|-161
33.088 114|70|-259
33.418 115|42|-237
33.698 116|17|-72
33.918 117|53|-326
34.298 118|-48|331
34.558 119|40|-269
34.868 120|55|-1034
35.958 121|33|33
41.298 X122|5340|5340

If there is a blank line after the 41.298 entry,
a time instant at time 0.0 is added with the label
"122".

It would be useful to ignore all blank lines
in the data file (I haven't tested blank lines
in the middle/start of the file yet...).