Fix links in documentation.

Some method links in connection.rst still don't light up in scaladoc
(but at least the pages are now correct). They are probably wrong but
guessing the right ones is a nightmare. Scaladoc needs to add a way to
get proper links out of the generated pages to make this usable.
Update documentation for Lifted Embedding

- Better explanation for lifting
- New "Compiled Queries" feature
- MappedTo for automatic mapping of column types
- Fix links to API docs
- Fix overflow scrolling in new docs theme
Improve applicability of .run and .list (by not requiring knowledge about the packed type)
removed .selectStatement from Invoker (in favor of Executor) because of ambiguous implicits
Allow UnshapedQueryExecutor to be extended by profiles.

We already allow this for the standard QueryExecutor. We need the same
for UnshapedQueryExecutor in order to add the "selectStatement"
method at the JdbcProfile level.

We also add an "executor" method that will compute the real (shaped)
executor for caching it in user code (analogous to the existing
"executor" field in QueryExecutor).

Test in MainTest. Fixes issue #548.
Add migration guide 1.0 -> 2.0
Improved Lifted Embedding documentation.

- Use matching examples for plain and Rep types
- Show typical SQL statements
- Remove "soft insert" code snippet and paragraph
- Some small fixes
Refactoring of the user manual.

- Lifted Embedding chapter split up into Schemas, Queries and
  User-Defined Features.
- Overview of the query APIs in the Introduction chapter.
- Move Slick Extensions chapter further up, Direct Embedding
  and Slick Testkit down to the bottom.
- Clearly mark Direct Embedding as experimental.
- Put the Migration Guide near the top.
Introduction updates

* Add equivelent SQL to the first example
* Add link to Activator template in "What is Slick?"
* Change the features to match the home page
* Add code examples for the features
* Remove the quick overview since there is now a link to the Hello Slick template and we should rely on the Getting Started section to cover that content
Getting Started improvements

* Add Activator templates as the default path
* Replace the dependencies section with info on how to add Slick to an existing app
* Remove reference to example code (Note: We could possibly add references to the code in the Activator template but I'm not sure yet how that would work best.)
Rename Invoker.to to Invoker.buildColl and deprecate the old name.

This will free up "to" for use in the new encoding of type constructors
into Query for Slick 2.1. We should be able to get rid of Invokers in
2.1 and do everything with the simple Executor.
Fix driver bugs and add some scaladoc
Fix withDynTransaction.

Run the block in a dynamic session with a transaction, don't try to wrap
a session function for the block in a transaction (which will fail) and
then run it.
Add meta model and creation from jdbc meta data
Add code generator for models (aka type-providers)
Merge pull request #541 from slick/tmp/type-providers-simple-rebased

Code-generation based type providers
Fix unwanted dependency on scala reflect
Merge pull request #255 from slick/tmp/moreGeneralAppliedInvoker

Improve applicability of .run and .list
Merge pull request #551 from slick/tmp/extensible-unshaped-query-executor

Allow UnshapedQueryExecutor to be extended by profiles.
Merge pull request #556 from slick/tmp/deprecate-to

Rename Invoker.to to Invoker.buildColl and deprecate the old name.
Merge pull request #571 from slick/tmp/fix-dyn-transaction

Fix withDynTransaction.