Add a small helper script to clean the --cachedir from cron.

This is only useful when the --cachedir is a tmpfs mount.
Ship the misc tools in the tarball.
Drop redundant call to AC_PROG_MKDIR_P.

This reverts commit fc792d9edf4cb8b08cbad5bdf349a0c5b99228e6.

After 70b8d1c, Automake's mkdir_p is now used. Automake provides mkdir_p
via AM_INIT_AUTOMAKE since 1.7b [1]; Automake >= 1.10 provides mkdir_p too,
by wrapping around Autoconf's MKDIR_P (via AC_PROG_MKDIR_P) [2]. Thus we
need not call anything to provide mkdir_p.

[1] http://git.savannah.gnu.org/cgit/automake.git/tree/ChangeLog?id=Release-1-7b#n51
[2] http://git.savannah.gnu.org/cgit/automake.git/tree/ChangeLog?id=Release-1-9b#n219

This also benefits older Autoconfs (ie. < 2.60) which do not provide
AC_PROG_MKDIR_P.

Tested on:
 - Solaris, Autoconf 2.59, Automake 1.8.3
 - Ubuntu,  Autoconf 2.68, Automake 1.11.3

Signed-off-by: Benoit Sigoure <tsunanet@gmail.com>
Allow -w and -c to accept floats.

Signed-off-by: Benoit Sigoure <tsunanet@gmail.com>
Update NEWS with changes made for v1.1.0.
Add a workaround to prevent the graph from being dragged around.

On mouse-down events we need to prevent the event's default behavior as
it may make the browser start dragging the image around.  We don't want,
we want to handle the dragging ourselves for the drag-to-zoom box.

However preventing the event's default behavior has another obnoxious
consequence: it doesn't remove the focus from whatever had it previously,
which may cause the image to not get reloaded if a text field was being
changed and the user simply "clicked away" on the image.

The workaround consists in keeping an invisible, useless TextBox
around, and when the focus needs to be removed, make it visible,
give it the focus, just to make it invisible again.  Yuck.