asn1: use LTC_SET_ASN1 macro to access ltc_asn1_list elements
fix constructed type identifier check
bypass constructed type identification for sets / sequences
unwind conditional expressions

I prefer readability
add missing types to decode routines
change the ASN1 type to be a typedef

replace all 'default' cases in the switch statements
add missing check of the OID
trim trailing spaces
add missing ASN1 types in der_encode_set()
use DO() macro when calling API functions in tests
Merge branch 'fix/asn1' into develop

This closes #49

[skip ci]
some more ASN.1 fixes

these should have been in #49
build.sh: improve diff parameters
Merge branch 'fix/mingw64' into develop
trim trailing spaces
fix CC parameter given to make in testprof folder
math: change get_digit() return value

unsigned long is 32bit wide when compiling with the compiler flag "-mx32"
but the digit size of the math libraries is still 64 bit which lead to
the buggy ecc code.

Therefore define a new type ltc_mp_digit with the correct width and use
that as return value of get_digit()

Has been tested with all three math providers
fix compiler warning when compiling with GMP_DESC
Merge branch 'fix/x32' into develop

This closes #51
RSA in case CRT optimization parameters are not populated

rsa_exptmod(), ran on the private key, makes use of CRT optimization
parameters. In some use-cases, the given key does not include the
optimization parameters.

This patch allows rsa_exptmod() to run without the CRT parameters,
using directly mp_exptmod().

Signed-off-by: Pascal Brand <pascal.brand@st.com>