Install Instiki on cygwin

Get sqlite sources.
Compile it as said in README.
To generate the shared library explicitly, we need to do:

make sqlite3.dll

Then, install the library:

mkdir /path/to/instiki/lib/native/i386-cygwin
cp sqlite3.dll /path/to/instiki/lib/native/i386-cygwin/

Update /path/to/instiki/vendor/sqlite3-ruby/sqlite3/driver/dl/api.rb to add:

when /i386-cygwin/
  "sqlite3.dll"

where the sqlite library is dynamically loaded.