Fix a few things found by valgrind. There will be more of these.

Fix a few things found by valgrind.  There will be more of these.

* bytecode.c (yasm_bc_create_insn): Initialize operands list if none were
given.
* section.c (yasm_object_destroy): Free filenames.
* gas-token.c (fill): Use memmove instead of memcpy on overlapping memory
copy.
* nasm-token.c (fill): Likewise.
* elf.c (elf_secthead_destroy): Free size member.

svn path=/trunk/yasm/; revision=1399