Bug 710818 - Overflow safe wrappers for acos/asin (now really)

acos() and asin() are only defined in a certain range. Implement some
range/overflow safe wrappers rather than potentially passing infinite
to other modules (e.g. cairo did assert() on it.)

Additionally check for !isinf() in cairo plug-in (should not trigger
anymore).

(cherry picked from commit 9a1f90855fb65ae1f129ccf5687bdf5ad3a37a55)

Conflicts:
	plug-ins/cairo/diacairo-renderer.c
[warnigectomy] Use -Werror=... rather than --std=c89

On win32 we still need c89/c90 w/o gnu extension due to msvc6 use.
But --std=c89 is very strict, e.g. it prohibits single line
comments.
The following -Werror= reject constructs which break the Windows
build

 -Werror=declaration-after-statement
 -Werror=implicit-function-declaration

There might be more conmstructs to avoid, but these arte the most
pressing. Actually the second is turned into an error explicetly
on Windows, too. But the first one is a compiler limitation.

(cherry picked from commit 65b4ff6191f210201acfe11f8f969e4d910b1928)
Bug #600983 - Use automake's silent rules for nicer build

For now only tested with automake 1.10.2, but it does not disturb the
build there. Patch from Jon Dufresne.

(cherry picked from commit 3d66c398445ba92a094e899f6253cbac0d16d472)
[warningectomy] implicit conversion from enumeration type

implicit conversion from enumeration type 'enum _cairo_font_slant' to
different enumeration type 'cairo_font_weight_t' (aka 'enum
_cairo_font_weight') [-Wenum-conversion]
                          DIA_FONT_STYLE_GET_WEIGHT (style) <
DIA_FONT_MEDIUM ? CAIRO_FONT_SLANT_NORMAL : CAIRO_FONT_WEIGHT_BOLD);

^~~~~~~~~~~~~~~~~~~~~~~

(cherry picked from commit 36104262d2d3cffb1ac61ed3ce6585ec306904c1)
Fix 'UML - Classicon' property 'type' flags (especially being optional)

The property flag initialization was wrongly using the logical OR operator,
it was meant to be bitwise OR. Occurrence only in the master branch.

(cherry picked from commit 1aaf9592cffbb03c199cddb85fcc63b06cad0f8e)
[scan-build] Unitialized argument

In case of malformed spline an uninitialized pointer was passed to
g_free()

http://clang-analyzer.llvm.org/scan-build
(cherry picked from commit c308a61b42f4dccb820cdd6bafad2c97b126cd36)