gschem: Update Brazilian Portugese translation.

Closes-bug: lp-1099699
gschem: Remove unused variable assignment in x_event_key()
gaf: Use g_setenv() instead of setenv().

Using bare setenv() was causing problems with Windows builds.

Reported-by: DJ Delorie <dj@delorie.com>
gschem: Fix typo in comment
gschem: Update documentation for tree_row_activated

Commit 69f7faf introduced a behavior change in tree_row_activated.
This patch updates the associated Doxygen documentation.
gschem: Fix inconsistent double-click behavior in component selector

Double-clicking a symbol in the "Libraries" tab of the component selector
closes the dialog (introduced by commit 69f7faf).  This patch makes this
behavior also available in the "In Use" tab.
libgeda: Use bounding box accessor in o_pin_update_whichend
Pass TOPLEVEL object to shortest_distance functions

The shortest distance between a complex or text object and a point
depends on the object's bounding box which in turn depends on the
rendered_text_bounds_* and show_hidden_text fields of the TOPLEVEL
context.  Therefore, a TOPLEVEL context is logically required to
obtain a useful shortest distance.
libgeda: Use bounding box accessor in shortest_distance functions
gschem: Use bounding box accessor
gschem: Just invalidate bounds of moved complex object

There is no need to recalculate the bounding box immediately;
world_get_single_object_bounds will do that when required.
Replace flag w_bounds_valid with TOPLEVEL reference

The bounding box stored with an object depends on the TOPLEVEL
context passed to the first call to world_get_single_object_bounds.
Calling this function with another TOPLEVEL object returns the stored
bounding box which may not be valid for that context.

This commit replaces the boolean validity flag with a reference to
the actual TOPLEVEL context for which the bounding box was calculated.
world_get_single_object_bounds checks if this matches the requested
TOPLEVEL context, and if not, recalculates the bounding box.
Don't recalculate bounding box on object updates

Since the bounding box of an object is not read directly any more,
updating it can be deferred until it is actually necessary.
libgeda: Remove recalc functions

- Object bounding boxes are now calculated on-demand by
  world_get_single_object_bounds,
- other functions are discouraged to use the recalc functions directly,
- keeping them around adds extra complexity,
so we might as well remove them.
Update homepage URL in gschem about dialog.
libgeda: Fix typo in o_pin_update_whichend

Example symbol reproducing the bug:
v 20020825
P 305 0 305 100 1
P 305 200 305 300 1
libgeda: Remove dead code

The bounding box of a pin has PIN_WIDTH_NET / 2 extra space in all
directions (see world_get_line_bounds in o_line_basic.c).
Enable support for "silent" build rules

Silent rules are disabled by default. Configure with
`--enable-silent-rules' or run `make V=0' to enable them.

You can run `make -s' to get even less verbose output.
gnetlist: Fix `subr' argument to SCM_ASSERT
libgeda: Fix broken macro EDA_IS_CONFIG_CLASS