Add a simple tool (written in C++11) to print out section numbers.
Small improvements to sections.cpp.
tools/sections: Ignore commented out section commands

This avoids the tool recognizing lines like:

%gram: \rSec1[gram.over]{Overloading}

as the start of a new section.
internal change: Remove unused \exposrc macro.
internal change: Remove \exposr macro.

\exposr was the same as \expos anyways (it probably meant something in the
past, but doesn't seem to anymore) so replace all occurrences with \expos.

Also update changemarks.sh to drop expos and exposr.
Remove affiliation from working draft cover.
[forwardlist.modifiers] Properly indent Returns: paragraph.

Closes #200.
[diff.mods.to.headers] Remove redundant (and wrong) count of C headers.

Also remove italics as this part is not defining the term "C headers".
[depr.c.headers] Fix count of C headers.
[cpp.predefined] Replace "integer constant" with "integer literal" throughout.

The single correct name for these in the draft is "integer literal".

Thanks to Richard Smith.

Closes #193.
Capitalize "Effects: Equivalent to" consistently throughout the draft.

"Equivalent to", rather than "equivalen to", is the consistent and
predominant form.

Closes #196.
[depr.strstreambuf] Add missing closing parenthesis.
Update previous document number.
N3786 Prohibiting "out of thin air" results in C++14.
N3776 Wording for ~future.
CWG1583 Incorrect example of unspecified behavior
CWG1575 Incorrect definition of "strict pointer safety"

Fixed typo in proposed wording: "stotate" should have been "storage".
CWG1648 thread_local vs block extern declarations
LWG2141 common_type trait produces reference types

I used the decay_t<T> form of decay instead of typename decay<T>::type.
LWG2246 unique_ptr assignment effects w.r.t. deleter