RAW encdec: overindexing of the buffer

Summary

The buffer can be overindexed in the RAW decoder during the decoding of the last field.

Steps and/or TTCN-3 code to reproduce

Use the test case of the Issue #557 C++ Run the test with valgrind Java Just run the test case

What is the current bug behavior?

C++, Valgrind

==13478== Invalid read of size 1
==13478==    at 0x17EFE2: TTCN_Buffer::get_byte_align(unsigned long, raw_order_t, raw_order_t, unsigned long) (in /home/ethgasz/proba/a/proba)
==13478==    by 0x17F6FD: TTCN_Buffer::get_b(unsigned long, unsigned char*, RAW_coding_par const&, raw_order_t) (in /home/ethgasz/proba/a/proba)
==13478==    by 0x1881C2: HEXSTRING::RAW_decode(TTCN_Typedescriptor_t const&, TTCN_Buffer&, int, raw_order_t, bool, int, bool, RAW_Force_Omit const*) (in /home/ethgasz/proba/a/proba)
==13478==    by 0x13F2E4: proba::R4::RAW_decode(TTCN_Typedescriptor_t const&, TTCN_Buffer&, int, raw_order_t, bool, int, bool, RAW_Force_Omit const*) (in /home/ethgasz/proba/a/proba)
==13478==    by 0x13E9E9: proba::R4::decode(TTCN_Typedescriptor_t const&, TTCN_Buffer&, int, ...) (in /home/ethgasz/proba/a/proba)
==13478==    by 0x1531C5: proba::R4_decoder(OCTETSTRING&, proba::R4&, UNIVERSAL_CHARSTRING const&) (in /home/ethgasz/proba/a/proba)

Java: Index overflow