bump ver to 0.6

Signed-off-by: etienne <etienne.basset@ensta.org>
Merge tag 'v0.6' of https://github.com/ccie16798/subnettools

new feature/command, ipinfo :
subnettools ipinfo 'subnet' can give the following informations about 'subnet'
- network address, last subnet address
- known prefix membership (IPv6 global addresses, RFC 1918 private subnet, multicast, etc...)
Decoding of following addresses :
- Teredo
- IPv6 multicast (including embedded RP)
- 6to4
- ISATAP link-local address
- IPv4 glop
- rfc 6052
- EUI-64 Interface ID

example :
[etienne@ARODEF subnet_tools]$ ./subnet-tools ipinfo FF72:340:2001:DB8:BEEF:FEED::32
IP version : 6
Network Address : ff72:340:2001:db8:beef:feed:0:32/128
Address   Range : ff72:340:2001:db8:beef:feed:0:32 - ff72:340:2001:db8:beef:feed:0:32
Previous subnet : ff72:340:2001:db8:beef:feed:0:31/128
Next     subnet : ff72:340:2001:db8:beef:feed:0:33/128
IPv6 multicast address
Scope : Link Local
Flags : 7
R=1, Embedded RP
P=1, based on network prefix
T=1, dynamically assigned prefix
Embedded RP Address : 2001:db8:beef:feed::3
        32-bit group id 0x32 [50]
Merge branch 'SCANF' of https://github.com/ccie16798/subnettools into SCANF
[BUG] mask2ddn was idiotic in case mask = 32

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[MAJOR] make consume_valist_... a MACRO

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[MAJOR] since va_list passing to other functions seems BUGGY, handle it a new way :
parse_conversion_specifier always should have a struct sto ARGUMENT instead of ap
it will then restore to ap via a MACRO (consume_valist_from_object) that was a function

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[HELPER] add strxcpy_until helper; strxcpy_until(buffer, "[abcdfdfdf]sdfdsfdsf", sizeof(buffer), ']')
buffer will be "[abcdfdfdf]" (unless sizeof(buffer) is not large enough)

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[TEST] trest strxcpy_until

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[HARDENING] strxcpy_until is __attribute__ ((warn_unused_result));

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[MINOR] use strxcpy_until instead of open-copy

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
[MAJOR] now char range is correctly found after x*
.*(expr) is now evaluated correctly

Signed-off-by: etienne basset <etienne.basset@numericable.fr>