Skip PCRE tests on Windows

These constantly fail for silly reasons like line endings or
not having the French locale installed.

May as well just save a manual step and needing to refer people
to an easily-missed item in README.windows.md.
Start developer documentation
Fix bounds error in forward-i-search
Bind remaining control characters in the search keymap

New functionality:
  ^L clears the display
  ^N and ^P iterate through the next or previous result
  ^G and ESC-ESC cancel search mode
  ^W erases the previous word to whitespace
Merge pull request #6642 from tkelman/patch-4

Skip PCRE tests on Windows
fix #6656
make countnz not depend on zero(T)

clarify docs for find(). closes #6528
remove Cbool from docs, as it does not exist (ref #6529)

I don't know what the calling convention is for C99 bool, so we'll have
to deal with this later.
fix #5876, static parameters in macro expansions
fix breakage from 118c02e4fa0e16179331edf85456c22c47da9da7
Fix #6693: Calculate correct length when pasting strings with multi-byte unicode characters
Merge pull request #6694 from mbauman/unicode-paste

Fix #6693: Calculate correct length when pasting strings with multi-byte unicode characters
Add a REPL manual section: "Interacting with Julia"
Merge pull request #6673 from JuliaLang/teh/devdocs

Start developer documentation
Merge pull request #6697 from mbauman/doc-repl

RFC: Add a REPL manual section: "Interacting with Julia"
Merge pull request #6682 from mbauman/search-bounds

Fix #6671: Check search bounds and bind missing control characters in i-search modes
Clean up temp file litter
Replace zero(T) with 0 in sparse matrix code.
Merge pull request #6705 from tkelman/patch-4

Clean up temp file litter
readdlm improvements:

- speed up reading of large files if dimensions are known
- prefer doing two passes when offset storage may take too much ram
- moved readdlm into a module to contain symbols