Refactor LoadingStrategy for xsiframe linker and rename it to ScriptLoadingStrategy since it is not inherently tied to the xsiframe linker.

Bring it more in line with the XhrLoadingStrategy and give them API compatibility so the xsiframe linker could use either one.

Add features, such as retrying the download if it fails (like the XhrLoadingStrategy has)

Lay the groundwork for adding prefetching, although this will need some changes higher up in the runAsynch framework to finish

Review at http://gwt-code-reviews.appspot.com/1468802

Review by: zundel@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10383 8db76d5a-ed1c-0410-87a9-c151d255dfc7
25 files changed