modified to fix blank page fault. see openDefaultBrowser()
The previous implement use "http:about:blank" which will be processed by "prepare" and be considered as a file path, turning to "file://...", which is no doubt beyond expectation.
To fix it,firstly the "about:blank" is used instead. Next, a new "openDefaultBrowserImplPrep" proc is added, take place of the previous version of "openDefaultBrowserImpl"
1d6fd30afb