Merge pull request #8241 from danluu/symbol_hang

Fix hangs and segfaults when egregiously long symbol is used
Merge pull request #8251 from danluu/reflection_test

Add some tests for various reflection functions
Merge pull request #8253 from rfourquet/big-ranges

make `big` map ranges to ranges
Move negative base check inside ndigits0z and add a test for (unsigned, signed) case.
ndigits: don't take abs(n) if b < 0.
Throw error when bigint ndigits has a negative base.
Merge pull request #8111 from eschnett/cld

Implement cld
Merge remote-tracking branch 'julia/master' into ndigits_hang
Replace 'manual' cld with cld function now that #8111 has been merged.
Match previous ndigits0z interface.
add reflection and examples to test/Makefile
Packages incompatible with your Julia version

If a package doesn't have any tagged versions compatible with your julia
version, it complains that

```julia
FixedPoint's requirements can't be satisfied because of the following fixed packages: julia
```
It seems confusing to consider julia a fixed package, so I changed the
message to.
```
ERROR: FixedPoint can't be installed because it has no versions that
support 0.4.0-dev+473 of julia
```
Fix stdout/stderr redirect after tests that print to stdout and stderr.
Merge pull request #8275 from danluu/stdout_redirect_broken

Fix stdout/stderr redirect after tests that print to stdout and stderr
add zlib and expat in the right section of LICENSE.md
moji char predicates
update docs for character predicates
update helpdb.jl for character predicates
doc fix: rand(r) works also when r is a StepRange
doc fix: replace Range1 by UnitRange