v0.6.0

Features:

• Add cpp_dump::dec(), bin(), oct(), hex() manipulators
• Add cpp_dump::cont_indent_style option
• Fix some bugs and improve performance

Breaking changes:

• Remove cpp_dump::int_style10() (Please use cpp_dump::dec() instead)
• Shorten the names of some of the manipulators:
  cpp_dump::show_front() -> cpp_dump::front()
cpp_dump::show_middle() -> cpp_dump::middle()
cpp_dump::show_back() -> cpp_dump::back()
cpp_dump::show_both_ends() -> cpp_dump::both_ends()
cpp_dump::cont_index() -> cpp_dump::index()