Flexbox ios initial commit

Items now appear, but they should initially shrink and they don't

Add 15-ish tests for flexbox layout

Port reasonable flexbox test set

Fixing issues, adding unit tests

Moved from .tsx to .ts and used our ui/builder.parse

tns-platform-declarations/android/org.nativescript.widgets.d.ts

@@ -305,6 +305,9 @@
                     public flexGrow: number;
                     public flexShrink: number;
                     public alignSelf: number;
+                    public wrapBefore: boolean;
+                    public minWidth: number;
+                    public minHeight: number;
                 }
             }