filename tab completion
trim commas on tables list in wp db export

In running `wp db export --tables=$(wp db tables --url=local.dev/msstable/feta --scope=blog | tr '\n' ',')` the list of tables passed looks like `wp_4_posts,wp_4_comments,wp_4_links,wp_4_options,wp_4_postmeta,wp_4_terms,wp_4_term_taxonomy,wp_4_term_relationships,wp_4_commentmeta,` 

When the list is later explode()d, the trailing comma causes there to be an empty element in the array, and on export an extra table gets included (whatever is first alphabetically).
Merge pull request #1269 from trepmal/patch-2

trim commas on tables list in wp db export
tab completion re-fixed
Merge pull request #1270 from trepmal/completion

Completion
Correct line breaks
Add mention that each contribution should be on a separate branch.
Fix incorrect argument in example

Fixes #1276
Show generated password when creating a user

This is helpful to the end developer, and was accidentally removed in 17860a741218d6230720d43cafa1c32f6a8a5ed2
Update step to handle directories too
Test coverage for scaffolding plugin unit tests
Mark install script as executable after copy
Merge pull request #1275 from wp-cli/fix-1275

Display password when wp cli creates it
Merge pull request #937 from wp-cli/fix-937

install-wp-tests.sh should be executable
Add methods to DocParser for getting arg descriptions
Show param description when required param is missing
Don't be so grabby, and accommodate trailing whitespace
Support for detailed results from `WP_CLI::launch()` and `::launch_self()`
Better naming for these methods.
Include the key in the error response

This is later used to look up more details about the argument.