[TIMOB-24451] Fix init of ListView in ListViewProxy

[garymathews]

• In some cases property getter events are fired before TiListView has been initialised by its parent
• Make sure the view is available before returning section data

TEST CASE

• Project on JIRA

JIRA Ticket

[lokeshchdhry]

FR Passed.

Clicking on Actual -> Manifest -> Details -> Manifest -> Details -> Manifest -> Actual in the test app does not give sectionCount or sections as 0.

Appc Studio : 4.8.1.201612050850
SDK Version : Locally built 6.2.0
Mac OS Version : 10.12.3
Xcode Version : Xcode 8.3 Build version 8E162
Appc CLI AND Appc NPM : {"NPM":"4.2.8","CLI":"6.1.0"}
Ti CLI : 5.0.11
Alloy : 1.9.5
Node : v4.6.0
Nexus 6 running 6.0.1