Minor: rename variable
#830 "Itemset editor: fixup label/value if needed"
Minor: indent
Minor: indent
Add xxf:custom-mips attribute

This allows explicitly specifying which extension attributes on xf:bind are custom MIPs. If missing, backward-compatible behavior is enabled and any extension attribute is considered a custom MIP.
FB: Set xxf:custom-mips

At design time, we only need to evaluate fb:required. With this change, all other fb:* attributes do not evaluate at design time, which is good for performance with a large number of binds.
Add XPath request statistics for debugging
#834 "MIP evaluations are slow with many bind/@name"

- variables are pulled by MIP expressions as needed
- static MIPs directly point to expressions, without cache indirection
- with XPath analysis enabled, the same compiled expression is used
Fix #835 "Failing constraint should default to false()"
Minor: arrows
Fix section label editor font size
#177 "Open/close state of existing sections is lost when inserting new sections"

- remove unneeded recurse param for visitControls
- new ControlsIterator
- move dynamic state restoration scoping to Controls
- save and restore switch state for xxf:dynamic full and XBL updates
For #177: Simplify fr:section to just use xf:toggle

- This helps with Form Builder restoring switch state upon full/xbl updates, as we just have to restore switches, not instances.
- 9baea9f5c615ea4b227df2ed899cf97dc15c4a4a introduced changes to "Get code ready to use "data-bound" switch", but that made the code more complicated then needed.
Rename captcha-help -> captcha-alert
Move XFormsStaticState.documentWrapper to XPath.DocumentWrapper
Rename XXFormsValueChanged to XXFormsValueChangedEvent
Dispatch xxforms-replace event upon root element replacement
Implement #836 "Support for XPath id() function"

- update Dom4j DocumentWrapper to support external element index
- support for xxf:index-ids on instance
- doInsert returns list of inserted NodeInfo (was Item)
FB: use id() function when possible
Comment-out non-working \\@