Began migration guide
 Migration: Run ZF1 and ZF2 in parallel
Migration:
Chapter on namespacing added to migration strategy guide
Merge pull request #796 from ezimuel/feature/migration-docs

 Migration draft: Run ZF1 and ZF2 in parallel
[#796] Edited document for grammar and flow

- Also, added section markers
Merge pull request #797 from ralphschindler/feature/migration-docs-ralph

[WIP] Added chapter on namespacing ZF1 application code/classes
[#797] Performed edits

- Made sure structure was correct for rst
- Edited for grammar and flow
Added namespacer section to migration section
Merge branch 'feature/migration-docs'

Added initial migration documentation

Conflicts:
	docs/languages/en/index.rst