fix a mistake in symbol visibility description string table
add support for .SUNW_ldynsym symbol table section
(see https://blogs.oracle.com/ali/entry/what_is_sunw_ldynsym)
add support for solaris additional visibility specifications
(see http://docs.oracle.com/cd/E19963-01/html/819-0690/chapter6-93046.html#chapter7-27)
add support for -s option in elfdump
fix string handling for python 3 in elfdump
fix pep8 compliance for elfdump script
remove unecessary imports in elfdump