configure.ac: Added 'matio_cv_' prefix to variables used in AC_CACHE_CHECK calls
configure.ac: Added 'matio_cv_' prefix to variables used in AC_CACHE_CHECK calls

configure.ac: Enabled both shared and static libraries by default

tbeu/matio,tbeu/matio,MaartenBent/matio,NJannasch/matio,martinichka/matio-coder,NJannasch/matio,martinichka/matio-coder,CBL-ORION/matio-sf-mirror,tbeu/matio,CBL-ORION/matio,MaartenBent/matio,martinichka/matio-coder,MaartenBent/matio,tbeu/matio,CBL-ORION/matio-sf-mirror,CBL-ORION/matio,telehan/libmatio,MaartenBent/matio,telehan/libmatio