remove dead local variable wrap_bin_scripts

now, the job is done by a call to repos.should_wrap_bin_scripts()
Merge pull request #230 from fperrad/patch-1

remove dead local variable wrap_bin_scripts
Make `luarocks doc` return something meaningful even for rocks that are not installed.
Merge branch 'master' of github.com:keplerproject/luarocks
Have separate fs.dir and fs.list_dir functions.
The first returns an iterator, the second one a table.
Install default doc files if the rockspec does not include any.
Refactor and improve logic for detecting base directory.
When a server times out, stop using it and move down the mirrors list.
Add test for missing external deps. Improves coverage.
A bug was uncovered writing this!
Upgrade luacov
Added nil check for tsfd in http_request()

If the opening of the cache timestamp file fails, then
tsfd would be nil.  write is then invoked on it yielding:

  /usr/local/share/lua/5.1/luarocks/fs/lua.lua:592: attempt to index local 'tsfd' (a nil value)

This changeset simply adds the check for nil.  It does no further error
reporting, so luarocks doesn't crash, but it also doesn't report that the
cache was not updated nor that anything out of the ordinary happened.
Merge pull request #233 from neomantra/http_request_err

Added nil check for tsfd in http_request()
Remove repeated entry
Fix issue when source.dir got misdetected if URL ends with character 'c'!
How many years did this go undetected?
Flag -c is running too slow.
handle implict subdirectories when unpacking with LuaZip
use correct path for is_dir check
Merge pull request #235 from siffiejoe/unzip

handle implict subdirectories when unpacking with LuaZip
filter message when deps_mode="none"

On Buildroot, we call `luarocks make --deps-mode=none --keep foo.rockspec`
So, the message about missing dependency is confusing.

```
Warning: skipping dependency checks.
...
Missing dependency for cgilua 5.1.4-1: luafilesystem >= 1.5.0
```
Merge pull request #236 from fperrad/patch-1

filter message when deps_mode="none"