Implement Struct#size and Struct#length .
Suppress test script syntax warning.
do not reuse deleted entry. fixed
Merge pull request #2091 from take-cheeze/struct_len

Implement Struct#size and Struct#length .
Merge pull request #2092 from take-cheeze/test_syntax

Suppress test script syntax warning.
Merge pull request #2093 from mirichi/bug_fix

do not reuse deleted entry.