Fix bug #152: NpgsqlInterval different constructors different ToString

Take the days from the Timespan, then the remaining ticks.
NpgsqlInterval(long) now calls NpgsqlInterval(TimeSpan) to make TimeSpan
do the division work.
Largely inspired by commit fd99912a019a3e987edfba8511431c82ec3cd9a5 from
glenebob
Initial DDEX support (Entity Model)
DDEX: Remove NpgsqlDataObjectSelector, use default one, no longer need customization
DDEX: Make copy/paste drag/drop work
Npgsql: Rework NpgsqlConnectionStringBuilder to be more consistent
Npgsql: Fix bug in NpgsqlMetaData.xml, wrong CompositeIdentifierSeparatorPattern
Npgsql: Fix GetSchema for tables to return TABLE only
DDEX: TableForeignKeyColumn ReferencedColumn not support yet, have to change GetSchema()
Npgsql: Revert NpgsqlConnectionStringBuilder.resx to using 2.0 assembly
Npgsql: Fix typo Keywords.Host to Keywords.UserName
Make NpgsqlConnectionBuilder to throw the inner exception instead of TargetInvokeException when parsing invalid value
Fix MinPoolSize/MaxPoolSize check
Make NpgsqlConnectionBuilder keyword case insensitive
Fix GetSchema SQL on Contraints and ConstraintColumns when using restriction
Start working on VS2013 Pro.
Fix null reference exception.
Fix GetSchemata so that simple users can query schema list.
Accepts keyword INTEGRATEDSECURITY.
Implement TryGetValue so that DDEX works.
Added InstallationTargets for various environments.
Correct GetConstraints and GetConstraintColumns : use of "as" keyword to be compatible with postgresql 8.1
Merge pull request #1 from samy2/wwindcloud-patch-on-master

Correct GetConstraints and GetConstraintColumns : use of "as" keyword to...
Added NpgsqlDdexProvider to Vs2010/Vs2012/Vs2013.
Added License.rtf for NpgsqlDdexProvider vsix installer.
Version set to 1.0
Installed missing DLLs.
PM> Install-Package Microsoft.VisualStudio.Project.10.0 -Pre
PM> Install-Package VSSDK.Data.10
Step #1: Put Visual Studio SDK targets/tasks in source control
Step #3: Manually set the VsSDKInstall locations
Fix: Step #3: Manually set the VsSDKInstall locations
Step #8: Add the VSIXManifestSchema.xsd to allow VsixManifest validation on the build server