Add support for namespaces.

For details of the new feature, see
https://github.com/luarocks/luarocks/wiki/Namespaces

This ended up being a huge commit because of some major refactoring
motivated by the new feature:

* new modules for some object types:
  * `luarocks.queries` - all functions that look for rocks in local or
    remote repositories now use objects constructed by this module:
    query objects contain the name, namespace and query constraints.
    Dependencies in a rockspec are also stored as query objects.
  * `luarocks.results` - all individual results produces from queries
    are returned in this format: result objects contain the name,
    namespace, version, arch and repo.
* the `results` object was renamed to `result_tree`, to better
  reflect that it is not an array of `result` objects.
* `luarocks.vers` was removed, its functionality was moved to better locations.

Specifically on namespaces:

* Commands that take a rock `name` can now take `namespace/name`
  (and alternately `--flags=namespace` so that URLs can be
  also installed with a nominal namespace).
* Rocks installed from a namespace now create a `rock_namespace`
  file alongside `rock_manifest`, which is used when matching
  namespaced dependencies against locally-installed rocks.
* Using namespaced dependencies in a rockspec, requires
  `rockspec_format = "3.0"`.
* Tests under the `#namespaces` hashtag, all using a local repository.

1 files changed, 4 insertions, 3 deletions

diff --git a/spec/fetch_spec.lua b/spec/fetch_spec.lua
index 5f518e4d..79b160c1 100644
--- a/spec/fetch_spec.lua
+++ b/spec/fetch_spec.lua
@@ -3,7 +3,6 @@ local git_repo = require("spec.util.git_repo")
 
 test_env.unload_luarocks()
 local fetch = require("luarocks.fetch")
-local vers = require("luarocks.vers")
 
 describe("Luarocks fetch test #whitebox #w_fetch", function()
    it("Fetch url to base dir", function()
@@ -30,12 +29,14 @@ describe("Luarocks fetch test #whitebox #w_fetch", function()
 
       it("from #git", function()
          local rockspec = {
-            format_is_at_least = vers.format_is_at_least,
+            format_is_at_least = function()
+               return true
+            end,
             name = "testrock",
             version = "dev-1",
             source = {
                protocol = "git",
-               url = "git://localhost:20000/testrock",
+               url = "git://localhost/testrock",
             },
             variables = {
                GIT = "git",