Fix r2007 TOLERANCE entity

TOLERANCE entity need a has_strings bit.

json: protect from NULL or wrong _obj

fatal. Thanks to 7erryX (GH #1190)

CI: bump oda to 26.9

Fix some REAL xdata types

dwg_resbuf_value_type missed some REAL and POINT3D ranges.
Fixes GH #1178

Co-authored-by: Reini Urban <reini.urban@gmail.com>

oda: bump to 26.7

spec: use signed VERTEX_PFACE_FACE.vertind [BSd]

e.g. -5 instead of 65531

encode: fix dwg_set_dataflags

oops, critical encoder bug!
dataflags are reverse, if a bit is absent then the field needs to be used.
also the default with_factor is 1.0

thanks to Erfan Sadigh Nejati for finding this bug.
Fixes GH #1164

configure: detect emcc

and fix failing probes because of -Werror -Wlimited-postlink-optimizations
Fixes the configure & make part of GH #1073

Fix dwgadd error with bad --as version

indxf: fix empty CLASSES GH #1068