Ratio: import from Trunk
Ratio: import from Trunk
Ratio: import from Trunk
Chrono: inspect update+fix si example
Chrono/Ratio merge trunk version v1
Ratio: Fix #6498+merge from trunk
Ratio: document fix for #6498
Ratio: mergre from trunk: fixes #7075
Merge changes from trunk:

Fix PDF install rule so that it's explicit and automatically invokes a PDF build when specified on the command line.
So "bjam pdfinstall" will now build and install the PDF to the current directory.
This works around some problems that the previous versions had if the user did not have an FO processor installed (basically Daniel James was unable to build the HTML docs for the distribution if the pdfinstall rule was implicit).
Ratio: merge from trunk
Ratio: merge 80896
Thread: Merge 80946,80947
Ratio: merge from trunk 1.53
Ratio: warning removal