set consistent minimum versions for gcc and clang

- we require full C++11 support, so gcc 4.8.1 and clang 3.3 it is
- closes #268

Signed-off-by: Thomas Lauf <thomas.lauf@tngtech.com>

AUTHORS

@@ -87,3 +87,4 @@ Thanks to the following, who submitted detailed bug reports and excellent sugges
   Clément Hermann
   Saulius Krasuckas
   Tom Dörr
+  Joerg Kastning

ChangeLog

@@ -3,6 +3,8 @@
 - #245    Performance Issues
           (thanks to Tom Dörr, Shaun Ruffell)
 - #259    Migrate to python 3 enhancement
+- #268    Minimum required gcc version to build timewarrior
+          (thanks to Joerg Kastning)
 - #269    Do not load entire database for all commands
           (thanks to Shaun Ruffell)
 - #270    Stop with id should suggest modify command

INSTALL

@@ -11,8 +11,8 @@ In order to build Timewarrior, you will need:
   - make
 
 You will need a C++ compiler that supports full C++11, which includes:
-  - gcc 4.9   (released 2014-04-22)
-  - clang 3.4 (released 2014-01-02)
+  - gcc 4.8.1 (released 2013-03-31)
+  - clang 3.3 (released 2013-06-17)
 
 
 # Basic Installation

README.md

@@ -20,7 +20,7 @@ Building Timewarrior yourself requires
 * git
 * cmake
 * make
-* C++ compiler, currently gcc 4.7+ or clang 3.3+ for full C++11 support
+* C++ compiler, currently gcc 4.8.1+ or clang 3.3+ for full C++11 support
 * Python 3, for running the testsuite
 
 There are two ways to retrieve the Timewarrior sources: