Merge pull request pleco-rs#123 from sfleischman105/Beta-Branch

Refactoring + Cleanups

Merge pull request pleco-rs#120 from sfleischman105/Beta-Branch

Update `pleco` to 0.4.4 and `pleco_engine` to 0.1.5

Merge pull request pleco-rs#116 from sfleischman105/Beta-Branch

Update versions, Fix nightly breakage, slight optimizations

Merge pull request pleco-rs#111 from sfleischman105/Beta-Branch

Fixes for nightly changes, update pleco to 0.4.2 and pleco_engine to 0.1.3

Merge pull request pleco-rs#109 from sfleischman105/Beta-Branch

Update `pleco` to 0.4.1 and `pleco_engine` to 0.1.2

Merge pull request pleco-rs#105 from sfleischman105/Beta-Branch

Update pleco_engine to 0.1.1, added more docs