add LICENSE, update copyrights, add Migen install instructions

LICENSE

@@ -0,0 +1,29 @@
+Unless otherwise noted, LiteX is copyright (C) 2012-2015 Florent Kermarrec.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer. 
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution. 
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+Other authors retain ownership of their contributions. If a submission can
+reasonably be considered independently copyrightable, it's yours and we
+encourage you to claim it with appropriate copyright notices. This submission
+then falls under the "otherwise noted" category. All submissions are strongly
+encouraged to use the two-clause BSD license reproduced above.

README

@@ -5,7 +5,7 @@
                          Migen inside
 
                 Build your hardware, easily!
-                Copyright 2015 Enjoy-Digital
+             Copyright 2012-2015 Enjoy-Digital
 
 [> Intro
 ---------
@@ -19,7 +19,7 @@ LiteX is based on Migen.
 
 [> License
 -----------
-LiteX is copyright (c) 2015 Enjoy-Digital under BSD Lisense.
+LiteX is Copyright (c) 2012-2015 Enjoy-Digital under BSD Lisense.
 Since it is based on MiSoC, please also refer to LICENSE file in soc directory
 or git history to get correct copyrights.
 
@@ -45,7 +45,8 @@ boards:
 0. If cloned from Git without the --recursive option, get the submodules:
   git submodule update --init
 
-1. Install Python 3.3+ and FPGA vendor's development tools and JTAG tools.
+1. Install Python 3.3+, Migen and FPGA vendor's development tools and JTAG tools.
+  Get Migen from: https://github.com/m-labs/migen
 
 2. Compile and install binutils. Take the latest version from GNU.
   mkdir build && cd build

litex/soc/software/bios/main.c

@@ -523,7 +523,7 @@ int main(int i, char **c)
 	irq_setie(1);
 	uart_init();
 	puts("\nLiteX SoC BIOS\n"
-	"(c) Copyright 2015 Enjoy-Digital\n"
+	"(c) Copyright 2012-2015 Enjoy-Digital\n"
 	"(c) Copyright 2007-2015 M-Labs Limited\n"
 	"Built "__DATE__" "__TIME__"\n");
 	crcbios();