Fixed parsing of float literals.

Float literals were not parsed properly when their fractional part
exceeded 53 significant bits. This affected in particular math.PI
and math.E. Rather than reinventing the wheel, this patch reuses
C's strtod() implementation, which already does the heavy lifting
with respect to correctness, though some caution is necessary to
keep float parsing locale-independent.
More human readable `$`(float)

The output matches that of Python (eg 1e100, not 1.0e100), but also
reflects locale (assuming it was set using setlocale() before).
Tests for `$`(float)
json.== handles nil now
Fixed `==` for PTables, added test.
Add reversed proc
Fix to included last element in reversed
Change wordwrap to remove separators at newlines
Update news.txt
Add random() for openarrays
Improves docstring contents and visibility of paramStr and friends.
Add missing complex arithmetic procs
Add missing difference and  to sets module
More effificent TSet difference
Merge pull request #1363 from Araq/devel

Merge devel into master
Add TSet difference tests
Merge pull request #1361 from def-/setdiff

Add missing difference and  to sets module
Merge pull request #1360 from def-/complex-missing

Add missing complex arithmetic procs
Merge pull request #1353 from gradha/pr_paramstr_docstrings

Improves docstring contents and visibility of paramStr and friends.
Merge pull request #1342 from def-/wordwrap-change

Change wordwrap to remove separators at newlines