Clean up bjam vs b2 in Boost Build documentation

[Mateusz Loskot]

In Boost 1.47:

The official name of Boost.Build executable was changed to b2.

The current documentation, however, does not indicate this change and it still refers to bjam command in numerous places. Note, the *tools/build/v2/doc/history.qbk* files does not mention the renaming either.

I have discussed this issue in ​bjam vs b2 thread on the boost-build list.

Here is patch with attempt to add the missing clarification and replace old references to bjam with either Boost Build or b2, depending on the context.

By the way, which should be preferred in the documentation, Boost Build or Boost.Build? Currently, both forms are mixed randomly.

[Mateusz Loskot]

Patch with bjam vs b2 clean up

[Vladimir Prus]

(In [86745]) Update docs to use 'b2' everywhere.

Patch from Mateusz Loskot, with extra tweaks. Fixes #9304.

[Vladimir Prus]

(In [86746]) Replace "Boost Build" with "Boost.Build".

Refs #9304.

[Vladimir Prus]

Mateusz, to answer your question above, preferred spelling is Boost.Build.

Thanks for the patch!

[Mateusz Loskot]

Volodya, thank you for the docs update, lots of useful clarifications there.