SciDAVis - Improvements SVN-temp

- Reverted (accidental?) change in r764 causing peak detection to find the maximum *absolute* value. The resulting behaviour is a bit confusing, to say the least.

- Fixed bug #2973098 (Data Reader broken for Dates as x) and related problems.
In particular, DataCurve::tableRow() was broken for DataTime values as well as
for columns with non-unique values. Screen picker and the tracker text of
data picker have been modified to use the same output format as the
bottom/left scales (currently hard-wired, switching to top/right would require
a user interface to be made up). The status bar output of data picker uses the
same format as the underlying columns of the selected curve.

- Tagging version 0.2.4.

- Version bump to 0.2.4.

- README for Windows installer synchronized with the nsi script.

- Compatibility table access functions modified so as not to use deprecated
methods.

- Enabled docstring generation feature in SIP >= 4.10.

- Added column access using array notation. Calls like
t.column("xyz").setValueAt(0,3) are a bit lengthy, especially compared with
the now-deprecated t.setCell("xyz",0,3). Adding the shorthand notation
t["xyz"].setValueAt(0,3) will hopefully make the move towards the
column-as-objects paradigm less painfull.

- Added deprecation annotation to all Python methods marked as such in the
current draft manual, so that using them will generate a warning.

- Updated and rearranged Linux section on download page. Removed names of
package authors/maintainers, since the list was incomplete and trying to keep
it in synch with the developments in various distributions doesn't seem
feasible.

- Update of Czech translation by Pavel Fric.