translate Paths to valid dot-separated MongoDB collection names (Fixes #139)
add type information to RenderedTrees (Fixes #106)

use a single case class for RenderedTrees (but with alias constructors Terminal and NonTerminal)

nodeTypes for Workflow trees

nodeTypes for LogicalPlan (and annotated forms)

nodeType for None

nodeTypes for AST annotations

handle the umpteen AST node types in RenderTree instance
improve handling of nested paths
move much of the path wrangling into mongodb.filesystem
simpler path<->collection name translation
escape '$' in collection names
Parenthesized expressions fail to parse.

Added pending test.
Merge pull request #146 from sellout/minor-fixes

Parenthesized expressions don’t parse correctly.
cleanup
simplify result type for ls()
Merge pull request #144 from mossprescott/139-nested-paths

translate Paths to valid dot-separated MongoDB collection names (Fixes #139)
workaround for Travis' download issues
Merge pull request #145 from mossprescott/106-rendered-tree-type-info

add type information to RenderedTrees (Fixes #106)