dotnet: Remove reference to dotnet release command

- Currently not implemented...

Add abseil patch

- Add patches/absl-config.cmake

Makefile: Add abseil-cpp on unix

- Force abseil-cpp SHA1 to 45221cc
  note: Just before the PR #136 which break all CMake

Makefile: Add abseil-cpp on windows

- Force abseil-cpp SHA1 to 45221cc
  note: Just before the PR #136 which break all CMake

CMake: Add abseil-cpp

- Force abseil-cpp SHA1 to 45221cc
  note: Just before the PR #136 which break all CMake

port to absl: C++ Part

- Fix warning with the use of ABSL_MUST_USE_RESULT
  > The macro must appear as the very first part of a function
    declaration or definition:
    ...
    Note: past advice was to place the macro after the argument list.
  src: dependencies/sources/abseil-cpp-master/absl/base/attributes.h:418
- Rename enum after windows clash
- Remove non compact table constraints
- Change index type from int64 to int in routing library
- Fix file_nonport compilation on windows
- Fix another naming conflict with windows (NO_ERROR is a macro)
- Cleanup hash containers; work on sat internals
- Add optional_boolean sub-proto

Sync cpp examples with internal code
- reenable issue173 after reducing number of loops

port to absl: Python Part

- Add back cp_model.INT32_MIN|MAX for examples

Update Python examples

- Add random_tsp.py
- Run words_square example
- Run magic_square in python tests

port to absl: Java Part

- Fix compilation of the new routing parameters in java
- Protect some code from SWIG parsing

Update Java Examples

port to absl: .Net Part

Update .Net examples

work on sat internals; Add C++ CP-SAT CpModelBuilder API; update sample code and recipes to use the new API; sync with internal code

Remove VS 2015 in Appveyor-CI

- abseil-cpp does not support VS 2015...

improve tables

upgrade C++ sat examples to use the new API; work on sat internals

update license dates

rewrite jobshop_ft06_distance.py to use the CP-SAT solver

rename last example

revert last commit

more work on SAT internals

fix

ortools/sat/integer_expr.cc

@@ -15,8 +15,8 @@
 
 #include <algorithm>
 #include <memory>
-#include <unordered_map>
 
+#include "absl/container/flat_hash_map.h"
 #include "ortools/base/stl_util.h"
 #include "ortools/util/sorted_interval_list.h"
 
@@ -531,7 +531,7 @@ std::function<void(Model*)> IsOneOf(IntegerVariable var,
     CHECK(!values.empty());
     CHECK_EQ(values.size(), selectors.size());
     std::vector<int64> unique_values;
-    std::unordered_map<int64, std::vector<Literal>> value_to_selector;
+    absl::flat_hash_map<int64, std::vector<Literal>> value_to_selector;
     for (int i = 0; i < values.size(); ++i) {
       unique_values.push_back(values[i].value());
       value_to_selector[values[i].value()].push_back(selectors[i]);