Fix last 'matkaba' typo

This one bit me irl.
Merge pull request #25 from glts/fix-matkaba-typo

Fix last 'matkaba' typo
Cache plugin dir contents for performance
Fix and test maktaba#IsAtLeastVersion (was using matchlist wrong)
Add Plugin.AddonInfo() to fetch plugin metadata from addon-info.json
Get version from addon-info.json
Declare BadValue thrown from Plugin.AddonInfo() (for invalid JSON)
Rename s:GetSubdir functions
Merge pull request #30 from google/hasdir_performance

Cache plugin dir contents for performance
Switch back to version regex to extract MAJOR.MINOR.PATCH
Merge pull request #33 from google/version

Fix and test maktaba#IsAtLeastVersion (was using matchlist wrong)
Merge pull request #34 from google/addon_info_version

Get maktaba version from addon-info.json and add Plugin.AddonInfo()
Add basic details to addon-info.json
Add "name" to addon-info.json
Add addon-info.json for examples/helloworld/
Add detection for plugins manually added to runtimepath
Merge pull request #36 from google/addon_info_basic

Flesh out addon-info.json and add addon-info.json for helloworld
Merge pull request #39 from google/plugin_detect

Add detection for plugins manually added to runtimepath
Add tests for maktaba#plugin#Enter and fix bugs (ftplugin, error msg)
Merge pull request #41 from google/enter_bugs

Add tests for maktaba#plugin#Enter and fix bugs (ftplugin, error msg)