Vaxpress

- Added the preliminary documentation.
- New scoring function: DegScore
- CAI is turned off by default (`bicodon` replaces the role)
- Fixed plotting errors with small number of activated scoring functions
- `--default-off` makes all scoring functions inactivated by default
- "Full Scan" now uses all survivors round-robin rather than only the top ranker.
- Leaderboard now marks the ID of parent for the evaluated sequences.
- The report shows more information about the sequence.

- Shows progress bar while running LinearDesign.
- VaxPress now can run without iCodon.
- Command line argument `--offsprings` is renamed to `--population`.
- Adds new feature that periodically scan all possible single mutations for all unpaired bases. Use `--full-scan-interval` to change the behavior.

- `--boost-loop-mutation` allows mutations weighted to single-stranded regions
- Added cache for secondary structure prediction
- Optimal interval for GC ratio is narrowed to focused within ~0.35-0.65.