Allow hard-coded values to be set

Addresses the first part of issue #12 by making `autoclose`,
`keyboardNavigation`, and `multidate` settable properties.
Add demo documentation for changeable properties

Second part of issue #12, updated demo page for sl-date-picker to
document `autoclose`, `keyboardNavigation`, and `multidate` properties.
Add number as alternate `multidate` type
Merge pull request #101 from joshforisha/feature/date-picker-properties

Make date-picker properties configurable instead of hard-coded
Add properties for additional HTML attributes

Handles issue #19
Merge pull request #103 from joshforisha/feature/textarea-attributes

Add properties for additional HTML attributes
Update, correct property types to include string
Add unit tests for additional HTML attribute properties
Merge pull request #104 from joshforisha/feature/textarea-attributes

Additional updates to textarea attributes
Closes softlayer/sl-ember-components#77
Merge develop branch
Merge pull request #106 from notmessenger/EmberCLI

Closes softlayer/sl-ember-components#77
Closes softlayer/sl-ember-components#100
Merge pull request #107 from notmessenger/DemoAppChanges

Closes softlayer/sl-ember-components#100
Merge pull request #110 from softlayer/develop

Merge develop into master in preparation of v0.5.0 release
Entries for v0.5.0 release
0.5.0
Update Ember CLI version number (was missed in v0.5.0 release)
Merge pull request #111 from notmessenger/Version

Update Ember CLI version number (was missed in v0.5.0 release)