Refactor TemplateFileStream class using TemplateStream

[mikee47]

DataSourceStream

• [BC] Amend StreamType enumeration eSST_TemplateFile -> eSST_Template
• [BC] Make getStreamType() method const
• [BC] make id() method const
• Add virtual getName() method to provide generic way of getting filename from TemplateStream wrapper
• Add virtual isValid() method

TemplateFileStream

• Refactor as TemplateStream class to allow any other stream type to provide source template data
• Replace int with unsigned or size_t as appropriate
• Minor code improvements

HttpRequest

• setFile() method can use any ReadWriteStream-derived class, doesn't have to be FileStream.

[slaff]

@mikee47 rebase and push -f to update the code.

cd %SMING_HOME%
git checkout develop
git pull
git checkout feature/TemplateStream
git merge develop
# if the merge errored then
# git mergetool 
git rebase develop 
# if rebase failed
# git mergetool 

[slaff]

@mikee47 Did you have the time to test the PR with the HttpServer_ConfigNetwork sample?

[mikee47]

@mikee47 Did you have the time to test the PR with the HttpServer_ConfigNetwork sample?

Not sure. I'll do that test and report back. I'd also like to make this PR a bit more interesting so will add something to samples to illustrate using TemplateStream with flash strings instead of files.

[mikee47]

Re-tested with HttpServer_ConfigNetwork (lovely sample!) yes, I remember already doing this so works fine.