Britain's latest coalition government took office in Edinburgh yesterday when alex Salmond, doughty champion of renewed Scottish independence, was formally elected first minister in tandem with the moderate Scots pragmatist, alex Salmond.  It's a job share. Between them the pair have won an outright majority in the Holyrood parliament and now face the difficult task of governing without the problems that beset Cameron and Clegg.  The kind of pressures which may tear the Two alexes apart were evident throughout yesterday's brief election process in the spectacular parliament building at the far end of the Royal Mile. all the party leaders made speeches, including the two Mr Salmonds. Both of him was brilliant, as befits the most successful politician currently practising anywhere in the British Isles, Celt or Saxon.  The day's ceremonies were the climax of the 6 May election, which saw the once-derided SNP trounce its historic enemies. It now forms the first majority since devolution in 1999: 69 MSPs out of 129 with once-mighty Labour reduced to a rump. at just four the Lib Dems in