Re-initialize the ASN.1 structures on every import

That allows to import a key/certificate on a structure even if the
previous import failed.
doc update
doc update
Safer reinitialization of structures on re-import to avoid memory leaks.

That also adds the gnutls_pkcs7_t structure into the list of allowed to
re-import.
updated minitasn1
renamed rfc2818_hostname to hostname-verify

The file no longer follows RFC2818.
Added support for RFC6125 hostname comparison

That adds the dependency on libidn.
tests: added UTF-8 hostname comparison checks
gnutls_x509_crt_print() will print the IDNA A-label names as well.
doc update
tests: suppress valgrind warnings due to libidn
updated libtasn1
tests: copied valgrind suppressions to suite
tests: Added case sensitive checks in hostname verification
check for the correct version of libidn
win32: updated Makefile and added the ability build openconnect
use the windows API in windows even if iconv is available
Revert "removed pbits=1024, qbits=160 from the acceptable bit sizes in FIPS140-2 DSA parameter generation."

This reverts commit 110527d9bb9ca70a66ae8173769067f133fd3cf7.
prevent 1024-bit DSA parameter generation only when FIPS-mode is enabled.
doc update