Not quite correct description of adding aliases

See this page http://cakebuild.net/docs/fundamentals/aliases
when you add your dll to /tools folder - it will get nuked on rebiuld.

Here is description from @gep13 what should be happening there:

> within the bootstrapper, we have the concept of doing an MD5 Checksum on the contents of the packages.config file, in order to see if any depenedencies have changed.
> if a difference in checksum is detected, or if the checksum file doesn't currently exist, the tools folder gets nuked, and put back together based on the contents of the packages.config file, and any tools/addin pre-processor directives that are contained within the .cake file
> since the dll is just "loose" in the tools folder, it doesn't get restored
> to work around this, change line 164 of your build.ps1 file to the following Remove-Item \* -Recurse -Exclude packages.config,nuget.exe,Cake.SqlServer.dll
> and that should get you up and running again