Introducing: literal value replacements, i.e. `where row.Id={=id}` - use rarely, but to avoid query-plan poisoning

Fixes to ExecuteReader for new API; also adds ExecuteReaderAsync; also fix null parameters which broke in an unrelated pull request

Async cleanup; implement missing async methods based on multiple pull requests, but introducing CommandDefinition to preserve binary compatibility while allowing new options

Fix double?/decimal? conversions (with test); added (currently failing; acknowledges current state) test re missing members

Implement connection-string equivalence (similar to https://github.com/SamSaffron/dapper-dot-net/pull/80)

Fix Issue131

This fixes a bug found in CS 51509960 where the following sequence would
result in an InvalidOperationException being thrown due to an attempt to
access a disposed of DataReader:

- Perform a dynamic query that yields no results
- Add data to the source of that query
- Perform a the same query again

There was a small issue when SplinOn spaces between commas, for example:
splitOn: "AddressId, Id".
For more info see:
http://stackoverflow.com/questions/11042618/dapper-multi-mapping-issue

I have modified below line of code:
From: var currentSplit = splits[splitIndex];
To: var currentSplit = splits[splitIndex].Trim();

Also added a test called:
TestMultiMappingWithSplitOnSpaceBetweenCommas()

Ensure that when processing bools we do a "!=0" test; we don't just want to store `7` as a bool - that causes problems sometimes.

IL level type-remapping, so i8 / i4 are interchangeable, etc. This avoids issues on databases that return 1 as bigint by default, etc

tweak tests to represent this (and workaround)

Added [ActiveTest] to allow trivial debugging individual tests

Fix for issue #70
(http://code.google.com/p/dapper-dot-net/issues/detail?id=70) and also
related MS bug with DbType.Time
(https://connect.microsoft.com/VisualStudio/feedback/details/381934/sqlparameter-dbtype-dbtype-time-sets-the-parameter-to-sqldbtype-datetime-instead-of-sqldbtype-time).

Support for ExpandoObject (or at least, "dynamic" and dictionary-like) to be treated directly as a parameter

Updated DynamicParameters to allow inheritance of the AddParameters method when subclassing for TVPs

Rewrite of the schema-change handling; the "see if it errors, then recalc" is, it turns out, stupid.

Replicated a bug 'Dapper MultiMap doesn't work with splitOn with NULL
value' reported on SO http://stackoverflow.com/q/10744728/449906.
Dapper doesn't create an instance of the class if the first property
after split is mapped to a column with NULL value.

Support enums (and nullable enums) in Query<T>, and check (extra tests) that they work fine for regular T with an enum / nullable-enum member