v0.5.4

Improvements

• Asynchronously import qtconsole, matplotlib and scipy to boost startup.
• Implement append method to Table and SpreadSheet.
• Show viewer after some function calls.
• Improve dark-theme syntax style of QtConsole.

Deprecations

• Methods and menus that add cell widgets are all deprecated since its behavior is not compatible with row/column insertion/deletion.

Bug Fixes

• Fix switch headers.
• Fix pasting from numpy-style text.
• Fix Japanese and Chinese preedit text.