As discussed in issue19273, here are a pair of patches that correct factual errors in PCbuild/readme.txt in both 2.7 and 3.3.

The 3.3 patch makes the following changes:
- Remove Win2k mentions, it is not supported (Tcl nmake command also adjusted)
- MSVCRT9 -> MSVCRT10
- SQLite 3.7.4 -> 3.7.12, remove "(see below)" with nothing to see
- .vcproj -> .vcxproj, all occurrences 
- _bz2.vcxproj isn't as magical as it was made out to be, and it can clean itself
- nasmw -> nasm
- Remove untrue part of Building for Itanium section
- Update msdn link
- .vsprops -> .props
- Trim trailing space

Due to the large number of lines in the diff due to trailing space, I'll also be attaching a patch created by `hg diff -w` for ease of review.