Msys build

Context

This merge request brings a new build on Windows using MSYS2.

Major changes

• MSYS2 build is now supported for Windows platforms

Minor changes

• Apache 2.0 license has been added to each file (more or less)
• [Flow] Transpiration boundary condition and dummy coupler have been added to prepare Amaury's work on viscous/inviscid coupling

Tests

• Passed on ubuntu 18.04, debian (gaston)

flow/models/oneraM6.geo

@@ -177,7 +177,7 @@ Point(153) = {1.124337,1.196000,0.002498};
 Point(154) = {1.119873,1.196000,0.003082};
 Point(155) = {1.114592,1.196000,0.003771};
 Point(156) = {1.108341,1.196000,0.004581};
-Point(157) = {1.100939,1.196000,0.005523,msTeTp};
+Point(157) = {1.100939,1.196000,0.005523,1.5*msTeTp};
 Point(158) = {1.092167,1.196000,0.006570};
 Point(159) = {1.081765,1.196000,0.007741};
 Point(160) = {1.071292,1.196000,0.008870};
@@ -293,7 +293,7 @@ Point(269) = {1.060762,1.196000,-0.009957};
 Point(270) = {1.071292,1.196000,-0.008870};
 Point(271) = {1.081765,1.196000,-0.007741};
 Point(272) = {1.092167,1.196000,-0.006570};
-Point(273) = {1.100939,1.196000,-0.005523,msTeTp};
+Point(273) = {1.100939,1.196000,-0.005523,1.5*msTeTp};
 Point(274) = {1.108341,1.196000,-0.004581};
 Point(275) = {1.114592,1.196000,-0.003771};
 Point(276) = {1.119873,1.196000,-0.003082};
@@ -330,7 +330,7 @@ Point(5109) = {1.124337,1.196620,0.000000};
 Point(5110) = {1.119873,1.196773,0.000000};
 Point(5111) = {1.114592,1.196954,0.000000};
 Point(5112) = {1.108341,1.197168,0.000000};
-Point(5113) = {1.100939,1.197422,0.000000,msTeTp};
+Point(5113) = {1.100939,1.197422,0.000000,1.5*msTeTp};
 Point(5114) = {1.092167,1.197722,0.000000};
 Point(5115) = {1.081765,1.198079,0.000000};
 Point(5116) = {1.071292,1.198438,0.000000};